Containment systems and components for animal husbandry

ABSTRACT

Provided are animal containment systems and components, including single-use animal containment cages and modular rack units. Also provided are methods for assembling and using components of the animal containment systems.

RELATED APPLICATIONS

This patent application is a continuation of U.S. Utility patentapplication Ser. No. 11/300,664, filed on 13 Dec. 2005, entitled“Containment Systems and Components for Animal Husbandry,” naming DeeConger, Thomas Perazzo and Matthew d'Artenay as inventors, which (i)claims the benefit of U.S. Provisional Patent Application Nos.60/635,756, 60/690,811 and 60/717,826 filed on 13 Dec. 2004, 14 Jun.2005 and 16 Sep. 2005, respectively, entitled “Animal ContainmentSystems and Components,” naming Thomas Perazzo and Dee Conger asinventors, and designated by attorney docket nos. INO-1001-PV,INO-1001-PV2 and INO-1001-PV3, respectively, and (ii) claims the benefitof U.S. Provisional Patent Application Nos. 60/734,229 and 60/734,189,each filed on 7 Nov. 2005, entitled “Containment Systems and Componentsfor Animal Husbandry,” naming Thomas Perazzo and Dee Conger asinventors, and designated by attorney docket nos. INO-1001-PV4 andINO-1001-PV5, respectively. The content and subject matter of each ofthese patent applications is hereby incorporated by reference in itsentirety, including all text and drawings.

FIELD OF THE INVENTION

Described herein are containment systems and components for housinganimals. Such systems and components are useful in animal husbandry, forexample, such as for maintaining, breeding, observing and studyinganimals.

DESCRIPTION

Animal containment systems are utilized in a variety of applications,such as for animal transportation, breeding and maintenance. Animalscontained in the systems often are laboratory animals such as rodents,and such animals often are contained in a vivarium. Containment systemsoften include animal cages in which the animals are housed and a rackunit onto which cages are mounted. Animals contained in such systemsemit several gaseous and particulate contaminates that are health risksto housed animals and human personnel maintaining the systems.Accordingly, cages generally are designed for multiple use, whichrequires they are washed and sterilized about every week for two yearsor more in an animal containment facility, for example, especially in afacility practicing Good Laboratory Procedures (GLPs). Multiple-usecages generally have relatively thick walls and components often areconstructed from resilient materials that can withstand multiple washesand sterilizations. Air often is delivered to cages by a low-pressuresystem (e.g., a pressure of less than 0.5 inches of water). Typical rackunits generally are not modular and are not readily disassembled. As aresult, large pieces of equipment are required to cleanse the rackunits.

Due to these aspects of multiple-use and non-modular animal containmentsystems, a significant portion of animal containment resources is notutilized to house animals. Instead, resources for washing andsterilizing multiple-use components and non-modular components representa comparatively large fraction of the total resources required foranimal containment. Also, airflow delivered by low pressure systemsoften is not readily adjustable and a range of airflows often cannot beprovided to cages. Further, typical multiple-use cage designs oftenlimit air exchange within the cage volume and air often is not exchangedat efficient rates. Multiple-use cage designs also can presentdisadvantages with respect to contamination, such as requiringcontaminated air filter handling or exposure of cage components to theenvironment when a cage impacts a surface (e.g., a cage is dropped by auser or falls from an elevation), for example, which bear especially onhandling of animals in higher biosafety level animal facilities.

Provided herein are animal containment systems that comprise disposable,single-use components, which do not require washing and sterilizationfor re-use. The animal containment systems and components can be usedfor transportation of animals and can be used for containment of animalsfor research and breeding, for example. Cages of such systems oftencomprise relatively thin walls constructed from a polymer. Features ofthese cages described herein substantially reduce or prevent thepossibility contained animals damage the relatively thin polymericmaterial (e.g., gnawing damage). The low weight and relative flexibilityof single-use cages, as compared to thicker, rigid multiple-use cages,provide for cages less prone to breakage or disassembly upon impact.These features reduce the likelihood that cage contents (e.g., animals,animal contaminants and any harmful substances in the cage) are exposedto the outside environment upon impact (e.g., cage bases and coversremain sealed after impact). The provided cages and associatedcomponents also can be efficiently nested, thereby advantageouslyreducing required storage space. Ventilated systems provided hereinefficiently exchange air in cages and efficiently maintain temperature.Such ventilated systems can be operated at relatively high air pressuresand without adjustable valves, providing for airflow and air pressureuniformity and efficient airflow control across a range of airpressures. Also provided are animal containment systems that comprisemodular components, often components that are readily disassembled. Insome embodiments, rack units comprise one or more attachable anddetachable rack modules that are readily disassembled for washing. Theseand other features of the components disclosed herein can reduce theamount of resources required for animal containment, can enhance qualityof care afforded to the housed animals, and can minimize health risks tohuman personnel who care for or study the contained animals.

These and other aspects are described hereafter in the followingdescription, claims and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate embodiments of the invention.

FIG. 1 shows a top isometric view of assembled cage embodiments, such assingle-use cage embodiments. The figure shows a general overview of anassembled cage from the upper front perspective.

FIG. 2 shows an exploded view of the cage assembly in FIG. 1 from theupper rear perspective. FIG. 2 shows individual parts that comprise acage assembly embodiment.

FIG. 3 and FIG. 4 are YZ plane cross-sections (coordinates are shown inFIG. 1). FIG. 3 is a cross sectional view taken at the center of thewater bottle in an embodiment. FIG. 104 is a cross sectional view takenthrough the food tray (103) of an embodiment.

FIG. 5, FIG. 6, FIG. 7A, FIG. 7B and FIG. 8 are XZ plane cross-sections(coordinates shown in FIG. 1). FIG. 5 is a cross sectional view takentrough the end of the food trough of an embodiment. FIG. 6 is a crosssectional view taken through the end of the food trough, showing anorientation of the trough engaged with the cage base. FIG. 7A is a crosssectional view taken through the middle of the cage in an embodiment,and FIG. 7B is an expanded view of the encircled region of FIG. 7A. FIG.8 is a cross sectional view taken through the middle of a food troughembodiment, and shows airflow streamlines caused by food trough.

FIG. 9A and FIG. 9B show a top view of a cage base embodiment. FIG. 10Aand FIG. 10B show a side view of a cage base embodiment. FIG. 11 is asection view showing an interference fit connection embodiment of a cagebase and cage cover.

FIG. 12 shows a front isometric view of a cage cover embodiment. FIG. 13shows a side view of a top cover embodiment. FIG. 14 shows a top view ofa cover embodiment. FIG. 15 is a bottom view of the top cover and anaffixed filter shield.

FIG. 16, FIG. 17A and FIG. 17B show food tray embodiments. FIG. 16 is anisometric view of a food trough embodiment. FIG. 17A is a top view ofthe food trough embodiment. FIG. 17B is a side view of a food troughembodiment. FIG. 18A and FIG. 18B show water bottle embodiments. FIG.18A is an isometric view of a water bottle embodiment. Tapered shoulder(155) seals with the vertical surface of the top cover to form a seal.Tapered wall (105) allows for increased water capacity. FIG. 18B is afront view of the water bottle embodiment. Surface (157) is slightlytapered confers added strength to the neck region of the bottle. Taperedwall (158) allows for increased water capacity.

FIG. 19 shows a top isometric view of an assembled reusable cageembodiment. Shown is a general overview of an assembled cage embodimentfrom the upper front perspective. The reusable cage assembly is of asimilar design as disposable cage parts and assemblies shown in FIG. 1to FIG. 18, and therefore water bottles and food troughs areinterchangeable between single-use and reusable cages. FIG. 20 shows anexploded view of the cage assembly embodiment from the upper rearperspective. FIG. 21 is a cross sectional view taken at the center ofthe water bottle in a reusable cage embodiment. FIG. 22 is a close-upview of seal (311). FIG. 23 is a bottom isometric view showing gasket(313) surrounding the perimeter of cage lid (301). FIG. 24 and FIG. 25illustrate a removable filter assembly that can be installed in reusablecage covers.

FIG. 26 is a bottom isometric view of a rack module. FIG. 27 is acut-away bottom isometric view of a rack module.

FIG. 28 is an isometric view of the clamp assembly. Self-tapping screw(76) is used to tighten the clamp (73) onto manifold (74). Air fitting(72) is of any convenient geometry for receiving tubing, such asflexible tubing, that is connected to an air supply or air exhaustconnector. FIG. 29A is a cross-sectional view and FIG. 29B is a top viewof the clamp assembly.

FIG. 30 is a top isometric cut-away view of the upper right portion of arack module. FIG. 31 is a cross sectional view of a clamp (100) in FIG.30.

FIG. 32 is a front view showing two rack modules positioned forconnection. FIG. 33 is a right side exploded view of a rack module.

FIG. 34A is a bottom isometric of a shelf assembly (80) embodiment. FIG.34B is a front view of the shelf assembly (80) embodiment. FIG. 35A is aside view of the shelf assembly (80) embodiment and illustrates levercontainment. FIG. 35B shows handle (221) in the up position.

FIG. 36 is an isometric view of an supply air blower enclosure.

FIG. 37 is a top view of a supply blower showing airflow path.

FIG. 38 is a bottom isometric view of an exhaust blower.

FIG. 39 is a side view of a module assembly depicting exhaust airflow.

FIG. 40 and FIG. 41 show a controller embodiment. FIG. 42A and FIG. 42Bshow wiring diagram embodiments for a blower control module embodiments.

FIG. 43A and FIG. 43B show systems for monitoring cage parameters suchas airflow, air exchange and temperature regulation.

FIG. 44 is an isometric view of an entire system assembly embodimentwith three rack modules.

ANIMAL CAGES

Animal cage units often comprise a cage unit base member, a covermember, and an optional insertion member. An animal cage base sometimesis provided separately from a cover, the cover often can be sealinglyattached to the cage base and the cover often is readily detachable fromthe base. An animal and/or optional insertion member often is placed ina cage base before a cover is sealingly attached.

A variety of animals can be contained within cages described herein.Rodents often are contained within such units, including but not limitedto mice, rats, hamsters, gerbils, guinea pigs, chinchillas and rabbits.The animal can be transgenic, inbred, immunodeficient, lack one or morefunctional genes (e.g., knock-out animal), and/or can include one ormore xenografts. Examples of immunodeficient mice include nude mice andsevere combined immune deficiency (SCID) mice. Cells from cultured celllines, cultured primary cells or directly from another animal or tissue(e.g., biopsy) may be utilized for xenografts (e.g., cancer cells from ahuman). The animals contained in cages and systems described herein canbe utilized in a variety of manners, including but not limited tostudying cancer and other diseases, assessing parameters of potentialdrugs (e.g., toxicity, efficacy, maximum tolerated doses, effectivedoses and other pharmacokinetic parameters), producing and isolatingantibodies and producing and isolating cells useful for preparinghybridomas, for example.

Cage Bases

A cage base is of any geometry suitable for housing animals, such ascylindrical, substantially cylindrical, conical, rectangular, square,cubic, rhomboid and the like, for example. A cage base often comprises abottom member that supports a plurality of sidewall members (e.g., foursidewall members). One sidewall member often is referred to as the“front sidewall member” and the opposite sidewall member often isreferred to as the “rear sidewall member.” Opposing sidewall memberssometimes are parallel, substantially parallel, not parallel, rhomboid,substantially rhomboid or a combination thereof. In some embodiments,opposing sidewalls are not parallel, and are not vertical with respectto the bottom. In such embodiments, a sidewall, and sometimes allsidewalls, are at a non-90 degree angle with respect to the bottom, suchas an angle between about 91 degrees and about 105 degrees, an angle ofabout 92 degrees to about 98 degrees or an angle of about 95 degrees,for example. Such angled sidewall configurations (with respect to thebottom) can promote cage base nesting (described in greater detailhereafter).

Each edge junction or corner junction of a wall or walls and/or thebottom has a geometry convenient for manufacture and use, such as asharp edge, smooth edge or rounded edge. It has been determined thatcertain corner and edge geometries in animal containment componentsadvantageously reduce or abrogate the possibility of damage caused byanimal residents (e.g., gnawing damage by rodents). This resistance todamage caused by contained animals is especially applicable tosingle-use containment components having thin polymer walls (e.g., about0.01 inches to about 0.08 inches). Damage resistant edge and cornerorientations have been determined based upon a combination of (i) angleof edge or corner surfaces (in degrees) and (ii) edge or corner radius(in inches). The angle alpha between two surfaces is measured from theside of the surfaces on which an animal resides. When alpha is less than180 degrees, the edge or corner minimum radius may be zero. When alphais between 180 degrees and 360 degrees, a minimum radius can bedetermined by the following equation:

minimum radius=0.25/(tan((pi/360)(360−alpha))).

For example, minimum edge and corner radii of 0.02, 0.04, 0.07, 0.09,0.12, 0.14, 0.18, 0.21, 0.25, 0.30, 0.36, 0.43, 0.54, 0.69, 0.93, 1.42,2.86 and 5.73 inches often are incorporated when the corresponding anglealpha is 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300,310, 320, 330, 340, 350 and 355 degrees, respectively, in accordancewith this relation. Thus, provided are edge and corner angle/minimumradius combinations in accordance with the above relation.

Thus, a cage base often comprises rounded junctions of a suitableradius, which can minimize damage caused by gnawing or clawing of housedanimals, for example. Thus in some embodiments, bottom corners, eachformed at the junction of the bottom and two sidewalls, often are notsharp corners and often are smooth corners defined by a radius. Eachcorner in some embodiments is effectively split into multiple edges(e.g., three effective corners (111B) as shown in the FIG. 1), which canimprove crumple resistance to impact. Crumple resistance to impactprovides benefits of maintaining nesting efficiency, reducing potentialdamage caused by animal gnawing (e.g., impact can crumple a corner andintroduce a sharp edge on which an animal may gnaw), and maintainingcage integrity upon impact (e.g., not exposing the cage interior to theoutside environment). In certain embodiments, a corner is effectivelysplit into 10, 9, 8, 7, 6, 5, 4 3 or 2 corners, each often defined by aradius.

The top edge of one or more sidewall members often is contiguous with aflange portion that extends, often vertically, from the outer surface ofthe sidewall member. The flange sometimes forms a continuous surfacearound the top perimeter of the cage and its surface often is horizontalwhen the cage rests on its bottom member. The flange can be any width,sometimes about 0.03 inches to about 1 inch. The flange can increasecage base rigidity and sometimes is configured to mate with a portion ofa cover member, described further herein. In some embodiments, theflange includes an optional downward extending lip member, whichsometimes mates with a corresponding member of a cover to form adetachable seal. The profile of the lip member of the base is of anyshape to allow a fit with a corresponding structure on the cover, wherethe profile sometimes is curved, and sometimes is S-shaped, V-shaped orJ-shaped. The lip member and/or flange member of the cage base sometimesare shaped to deflect when mated with a cover member to form a sealbetween the cage base and the cover. The seal between the cage base andthe cover is of any convenient or useful type, including but not limitedto an adhesive seal, compression fit or interference fit, for example.The seal sometimes results from an interference fit of any suitableconfiguration, an embodiment of which is described hereafter in greaterdetail.

A cage base sometimes comprises one or more indents in a sidewall memberthat extends towards the interior of the cage base. One, two, three,four or more sidewalls sometimes include one or more indents, which canincrease sidewall rigidity. Sidewall integrity enhancement can providean advantage of increasing impact resistance to crumpling, advantages ofwhich are described above. The depressed surface area of an indent canbe trapezoidal or rectangular. The depressed distance of the indentvertical from a sidewall from which the indent extends often iscontinuous from the top of the indent to the bottom (e.g., the face isparallel to the side wall from which the indent is extended), and may begreater at the top of the indent, sometimes tapering from the topportion of the indent to the bottom portion. Such configurations allowfor nesting of cage bases when they are not housing an animal, asdescribed hereafter. An indent often is located in close proximity to abaffle or feeding structure integrated with or in association with acover member (described in greater detail hereafter), thereby reducingairflow along sidewalls of the cage base and increasing airflow parallelto and nearer to the cage bottom. An indent sometimes is configured toorient one or more optional cage insert members described hereafter(e.g., feeding tray), and sometimes it or a portion thereof is referredto as a “mount,” “cradle” or “support member” when utilized in thismanner. A mount is of any geometry useful for supporting and orienting acage insert member, and sometimes is an extension comprising a planarupper surface parallel with a base unit bottom surface. In someembodiments (e.g., FIGS. 2, 5 and 6), a mount or support membersometimes is formed by a wall of a cage base and a depression in theindent, and is of a shape adapted to receive a cage insert. In anembodiment shown in FIG. 5 and FIG. 6, the profile of the mount has aflat bottom extending to curved sides. The curved sides can include adetent (e.g., formed by surfaces 101B and 101C shown in FIG. 6) adaptedto receive a corresponding structure in the cage insert (e.g., surfaces103B and 103C of the feeding trough in FIG. 6). The horizontal end ofeach indent or mount sometimes is equidistant to an adjacent sidewall insome embodiments, and its horizontal midpoint thereby is located at themidpoint of the sidewall with which it is integrated. In embodimentsillustrated in FIG. 6, each mount supports each end of the feedingtrough, and extends away from the surface of the indent (e.g., about 1cm), sometimes substantially flush with the sidewall surface. A cagebase bottom also may include one or more indents, which also canincrease rigidity and crumple resistance.

A cage base may include one or more mounts located on an outside surfaceof a sidewall member or bottom member, which sometimes are referred toherein as “outer support members” or “outer guide members,” which allowfor convenient mounting of the cage into a rack unit. The outer supportmembers or outer guide members are of any configuration allowing formounting of the cage base into a rack unit member, and sometimes matewith or are supported by corresponding members in the rack unit. In someembodiments, a flange member contiguous with the top of one or moresidewall members serves as a guide member and/or support member. Incertain embodiments, a guide member and/or support member is a flange,projection, rib or groove located on the exterior surface of a bottommember and/or one or both cage sidewall members (e.g., sidewall memberadjacent to the front sidewall and rear sidewall), and often is parallelwith the top edges of the sidewall members. Such guide members andsupport members sometimes extend from the front edge of a sidewallmember, sometimes extend to the rear edge of a sidewall member,sometimes extend from a point in a sidewall member a distance from thefront edge, and sometimes extend to a point in a sidewall member adistance from the rear edge. Such members sometimes are oriented in themiddle half of the vertical length of a sidewall member, and sometimesare oriented in the middle of the vertical length. In some embodiments,guides are low profile, and sometimes are grooves or depressions, thatdo not substantially interfere with nesting of cage bases.

A cage base is manufactured from any material suitable for housing ananimal, such as a small rodent, for a time period of about one week orgreater. The material may be rigid, and often is a semi-rigid orflexible material. The cage base sometimes is constructed entirely, orin part, from a translucent or transparent material. Examples ofmaterials utilized for manufacture of a cage base include, but are notlimited to, polypropylene (PE), high-density polyethylene, low-densitypolyethylene, polyethylene teraphthalate (PET), polyvinyl chloride(PVC), polyethylenefluoroethylene (PEFE), polystyrene (PS), high-densitypolystryrene, acrylnitrile butadiene styrene copolymers and the like. Incertain embodiments, a cage is constructed from PET or PS (e.g., highdensity PS). Sidewall members and bottom members are of any thicknessfor substantially maintaining cage integrity for about one, two, threeor four or more weeks of animal containment, and the thickness sometimesis about 0.01 inches to about 0.08 inches. The sidewalls often are ofsubstantially uniform thickness. A cage base often is manufactured as asingle unit and by any convenient process, sometimes in an injectionmolding, thermoforming or vacuum forming process, for example. A cagebase often is packaged for shipment, sometimes as a single unit andsometimes with other like units (e.g., as a nested set describedhereafter). A cage base sometimes is washed and/or sterilized (e.g.,U.V. irradiation, gamma irradiation) prior to packaging. Cage bases canbe packaged in any material, including but not limited to materialscontaining polystyrene, polyvinyl chloride, low-density polyethylene andthe like.

Cage Covers

A cover often is provided separately from a cage base, often reversiblymates with a cage base, sometimes in sealing attachment, and is of anysuitable geometry allowing for attachment to the base. A cover memberoften comprises one or more members that directly mate with and sealwith one or more members of a base; sometimes has no side wall members;and sometimes is planar or substantially planar. A cover member isconstructed from any material that allows for animal containment forabout one week or greater. Materials for constructing a cover sometimesare selected to allow for sealing attachment to a cage base. Examples ofmaterials from which the cover can be constructed include thosedescribed above for cage bases. Sometimes the cover and base areconstructed from the same material and sometimes are of a similar or thesame thickness.

The cover often is flexible or semi-rigid. A cover member oftencomprises a substantially planar region and a flange region. Thesubstantially planar region often comprises one or more componentsdescribed herein. The flange region sometimes is embossed, can beraised, often comprises a region that extends downwards as a lip(referred to herein as a “lip”). A flange and optional lip region mayextend continuously around the perimeter of the cover. The profile ofthe flange and optional lip often correspond to a flange and optionallip on a cage base, and often allow the cover to seal with the base viaan interference fit. The flange and optional lip are of any shape toeffect an interference fit with the base, and sometimes are S-shaped,V-shaped or J-shaped, for example. A cover member sometimes comprisesone or more of a continuously solid surface, an imperforate surfaceregion, and/or a perforated surface region (e.g., a region containingair holes or a grid structure). A cover member sometimes comprises,sometimes within a substantially planar region, an aperture, a groove, achannel, a depressed or indented region, a bossed region, a rib (e.g.,an embossed rib or solid rib), and sometimes a combination of theforegoing. Such a structure or structures often are located near aheavier structure in the cover, such as around or near a water supplyreceptacle or a connector that receives a corresponding non-coverconnector. A cover member sometimes comprises other components, such asa filter, a baffle, a feeding structure, and/or a watering structure,holders of the foregoing, and combinations of the forgoing, where eachstructure is integral or provided as a component separate from the covermember. Edges or corners in a cover often are rounded, often defined bya radius and/or angle described herein for cage bases. A cover incertain embodiments may be rigid. A cover member may comprise acombination of a flexible region with a rigid or semi-rigid region, therigid or semi-rigid region sometimes acting as a frame that allows acover to be handled efficiently and conveniently when attaching it to acage base, for example. A cover or a portion of it sometimes istranslucent or transparent.

In some embodiments, a cover and base are adjoined in a “clamshell”arrangement, and share a common edge. There often is a seam or hinge ofthinner material at the common edge such that the cover can “fold” ontothe base. The common side in such embodiments often is a longer side ofthe cover and base opening where each is rectangular (e.g., one of thelonger sides of the rectangular cover and base in FIG. 1). A flange edgein the cover and a corresponding flange edge in the base may be joinedin such a clamshell orientation.

The cover member can be sealingly mated to the base unit in any suitablemanner, configuration and material that allow for attachment anddetachment. In some embodiments, a cover member can be attached anddetached from a base unit member multiple times. A cover often isdirectly mated to a base in any convenient manner, such as bycompression fit or interference fit (e.g., a snap interference fit,friction interference fit and the like), for example. In interferencefit embodiments, the cover often comprises a flange and/or a lip member(e.g., a lip having an S-shaped profile) adapted to mate with acorresponding member in the base, embodiments of which are describedherein. The cover may be sealingly attached to the base unit byelectrostatic pressure or by an adhesive. An adhesive may be applied tothe cover member, or to the top of the base member that joins with thecover member (e.g., a flange at the top of the base unit), and may beapplied at the time of manufacture. An adhesive may be mated with aremovable backing that exposes the adhesive when removed before thecover is sealingly attached to the top of the base unit.

A cover sometimes comprises an air filter. The air filter often isconfigured to filter components (e.g., particulates) in air exiting thecage. The filter is composed of any filter material useful for housinganimals, including but not limited to spunbonded polyester, pressed pulp(depth filter), a Reemay filter (e.g., Reemay 2024), high-efficiencyparticulate air (HEPA) filter and the like (e.g., U.S. Pat. No.6,571,738). The filter sometimes excludes particles 1-5 microns in sizeor 0.3-1 microns in size. The filter often is in effective connectionwith a portion of the surface area of a cover member, and often not theentire surface area of the cover member. In some embodiments, the filteris in effective connection with 80% or less, 70% or less, 60% or less,50% or less, 40% or less, 30% or less, 25% or less, or 20% or less ofthe cover member surface area. A filter sometimes is integrated with thecover (e.g., the filter is not reversibly mounted to the cover member),and may be provided separately from the cover. When provided separatelyfrom the cover, a filter often is placed in effective connection with aportion of the cover, often a perforated portion of the cover (e.g., aportion having air apertures or a grid structure). A filter may beaffixed to a cover in any manner, often by reversible attachment and/orsealing attachment, and in some embodiments, the filter comprises anadhesive, sometimes on the outer perimeter of the filter, sometimesacross the entire surface area of the filter, and often on one side ofthe filter. Where the filter comprises an adhesive, it sometimes isprovided with a peel-off backing that exposes the adhesive, and theadhesive often allows for reversible adhesion (e.g., the filter can beaffixed, removed or partially peeled back from the cover, and thenaffixed again, which can be repeated multiple times). A filter may beattached to a cover by a manufacturer of the cover, and/or may beattached/detached by a user. In some embodiments, the filter is inconnection with a flexible film, the latter of which is coated on asurface (e.g., the entire surface or a portion of the surface) with anadhesive. When an adhesive is utilized, it often is not substantiallytoxic to animals housed in the cage and sometimes is a food gradeadhesive. The filter and/or film often is adjacent to or in effectiveconnection with one or more apertures of the cover.

In certain embodiments, a filter is sandwiched between the cover and aholding member attached to the cover. The holding member often includesone or more apertures through which air can flow, and holding memberoften is sealingly attached to the cover (e.g., attached by anadhesive). In such embodiments, a substantial surface area of the filteroften is not in direct contact with the holding member, which canprovide an advantage of reducing potential gnawing damage caused by acontained animal (such a holding member also is referred to herein as a“filter shield”).

A filter sometimes is connected directly to a cover member or shieldmember and often is not connected directly to a cover of shield memberbut effectively filters air into or from a cage. In the latterembodiments, a filter can be located in proximity to an aperture orapertures of a cover member or shield member, for example, and filterair entering or exiting the apertures. Standing an air filter away fromsurfaces of the cover and optional filter shield(s) provides certainadvantages, such as permitting efficient airflow and protecting filtermaterial from possible damage caused by contained animals (e.g., animalscannot effectively contact the filter). For example, filter (104)generally has a small percentage of area open for airflow. Pore sizesometimes is about 0.5 microns and there may be approximately 1000 poresper inch. The corresponding percentage of open area for this type offilter is about 2%. A relatively large filter surface thereforesometimes is utilized to permit airflow through the filter withoutsignificant restriction or pressure drop. Filter dimensions in the coversometimes are about six (6) inches by about two (2) inches. Theresulting area available to airflow for a filter of these dimensions isabout 12 square inches multiplied by 2%. The area available to airflowwould be significantly limited by exhaust apertures in the cover if thefilter paper were in direct contact with the cover (e.g., the areaavailable to flow is that of the area of the apertures, which can be(the square of 0.125/4 multiplied by 27 holes multiplied by 2%). Thus,standing a filter away from apertures in the cover and optional filtershield(s) can significantly enhance airflow by allowing the entirefilter paper to breathe.

Characteristics of cages provided herein advantageously contain cagecomponents when the cages are exposed to physical impact. For example,combinations of (i) sealing attachment of a cage base to a cover, (ii)light weight of the cage base and cover resulting from thin walls, (iii)flexibility of the semi-rigid base and cover, and (iv) base cornergeometry (e.g., effectively split into more than one corner), reduce thepossibility that cage contents (e.g., animals, animal waste and cageadditives) are exposed to the outside environment as compared toreusable, rigid cages. In the event a cage is exposed to impact (e.g.,dropped or falls to a floor from an elevated position) these featuresadvantageously protect contained animals from the exterior environmentand protect personnel from cage contents. These features areadvantageous for application in higher biosafety level environments(described hereafter), for example.

A cover sometimes comprises a substance that scavenges emissions from ananimal in the cage. Emissions sometimes are gaseous or particulatecompositions, such as those resulting from exhalation (e.g., watervapor, carbon dioxide), urination and defecation (e.g., ammonia,microbes), and exfoliation (e.g., dander, hair follicles, allergens,fomites, microbes (e.g., bacteria, fungi and viruses)), for example. Thescavenging substance sometimes is a catalyst or is utilized incombination with a catalyst that breaks down an emission from an animalinto innocuous substances (e.g., biocatalyst). A scavenging substancesometimes is included in a filter or is located adjacent to a filter,and sometimes is located in another portion of a cage (e.g., on a floorand/or below a sub-floor). Any scavenging substance suitable for usewith animals can be used, such as charcoal or other form of carbon.

As described above, a cover member sometimes comprises a deliverycomponent for delivering a consumable element to a housed animal, suchas air, water or food. The delivery component sometimes is integral withthe cover, sometimes the cover is in contact with a separate deliverycomponent (e.g., a surface of the cover is in contact with a flangemember of a food trough), sometimes the cover comprises a holder orreceptacle for the delivery component, and sometimes the cover includesan aperture adapted to receive the delivery component.

In some embodiments the cover comprises one or more connectors adaptedto receive an air supply or air exhaust component or water supplycomponent (e.g., a nozzle or nozzle receptacle). A connector can be ofany geometry to receive a corresponding connector from an air supply,air exhaust or water supply component. The cage cover connector oftenmates with the air supply, air exhaust or water supply connector by asealing attachment, and often by a reversible connection, and theconnectors are of any suitable type. For example, the connection may bedefined by cylindrical, square, rectangular or conical side geometry,and flat, rounded, tip or point geometry for the top or bottom, forexample. The connecting member in the cover may be a protrusion or avoid (e.g., concave or convex, respectively) that receives acorresponding mating void or protrusion, respectively. In someembodiments the connector structure in the cover is a void thatcomprises two apertures, a larger aperture and a smaller aperture, wherethe larger aperture is spaced above the smaller aperture. In suchembodiments, the mating nozzle connector is seated, often reversibly, inthe void, thereby forming a substantially air-tight seal. In someembodiments the connector structure in the cover comprises a protrusionhaving an aperture, where the aperture is at the apex of the protrusion.In such embodiments, a void in the mating connector fits over theprotrusion in the cover, often reversibly, and forms a substantiallyair-tight seal. Connection geometry in the latter described embodimentscan provide advantages of (a) expanding air exiting an air supplyconnector along inner walls of the cover connector and other cover andcage surfaces, which expansion cools air in the cage and compensates forthermal load of a contained animal, and (b) substantially reducing orpreventing the possibility of damage caused by contained animals (e.g.,gnawing, clawing). FIG. 1 shows a conical convex connection member inthe cover, and the connection member may be conical concave in certainembodiments. The nozzle connector of the air supply component can beseated in the cover by hand or by any other method, and connection maybe a gravity fit, pressure fit, screw fit or another suitable fit. Insome embodiments, the conical connector is held in a carriage thatguides the connector into the cover. Such carriages sometimes areconnected to a rack unit, often to a shelf thereon, embodiments of whichare described hereafter. The conical void sometimes is located in anembossed region of the cover, where the top surface of the embossedregion sometimes is substantially elliptical. Where the cover comprisesa flange, the height of the embossed region sometimes is equal to orsubstantially equal to the highest point of the flange.

A connector, such as an air supply and/or air exhaust or water supplyconnector, sometimes is in contact with a channel. The channel is formedwithin the cover in some embodiments, and may be formed by raisedcorresponding raised portions on each side of the cover. The channel insome embodiments is formed by the mating of (a) a bossed portion of thecover and (b) a corresponding bossed portion in a filter barrier member.The channel often includes one or more apertures on the side oppositethe connector, such that air introduced through the connector may enterthe cage. In embodiments where the channel is formed in part by a filtershield, the filter shield may comprise one or more apertures. In someembodiments, two or more apertures are distributed across the length ofthe channel, which can provide an advantage of distributing orexhausting airflow across the width of the cage, or a portion thereof(e.g., across the Y-axis in FIG. 1). The channel may be of any suitableshape for permitting airflow: the channel cross section may be circular,ovular, semi-circular, semi-ovular, rectangular, square, rhomboid ortrapezoidal, for example, and the length of the channel may comprise orconsist of a linear, circular, triangular, rectangular, ellipsoid, arc,sinusoidal or zig-zag geometry, for example. The length of the channelsometimes is not entirely linear and sometimes it is non-linear. Thelatter embodiments provide an advantage of reducing adherence of afilter to the cover or a filter barrier as a filter surface cannotdepress as readily across a non-linear depression as a lineardepression.

In some embodiments, the cover comprises or is in connection with anairflow baffle. A baffle often extends downwards from the inner surfaceof the cover into a portion of the cage interior. A baffle often islocated between an air inlet aperture and an air exit aperture, therebydirecting airflow around the baffle. Sides of a baffle often are inclose contact or substantially contacted with sidewalls of a cage baseso that airflow is directed towards the bottom of the cage base and doesnot bypass the baffle along cage sidewalls. In some embodiments, a feedtray is configured such that a wall of the tray acts as a baffle.Directing airflow towards the bottom of the cage and then up through thetop of the cover is advantageous for purging gaseous waste from beddingmaterial located at the cage bottom and for reducing airflow requiredfor maintaining the animals. In some embodiments, the baffle is formedby a food trough in connection with a cover and a base that projectstowards the bottom of the cage base. The food trough in such embodimentsoften is a member separate from the cover and the base and rests on acradle (i.e., mount) formed in an indent within the cage base.

The cover may comprise a water supply component. The cover sometimescomprises an integral water supply reservoir to which an emitter isconnected or integrated. In some embodiments, the cover comprises awater supply receptacle or holder into which a water supply thatincludes an optional emitter is seated, and in certain embodiments, thecover comprises an aperture through which a water reservoir is fixedand/or suspended. Water supplies are described herein.

In some embodiments, the cover is connection with or comprises a feedsupply component, often referred to herein as a “feeder,” “food trough,”or “food tray.” The cover sometimes comprises an integral food tray, andsometimes is in connection with a member of a separate food tray modulewhen the cover is mated with a cage base. In some embodiments, the covercomprises a food tray holder into which a food tray is seated, and incertain embodiments, the cover comprises an aperture through which afood tray is fixed and/or suspended. Food trays are described herein.

The cover often is semi-rigid or flexible. A cover member may comprise asemi-rigid member, flexible member and/or a filter member. A semi-rigidmember sometimes forms a continuous perimeter around the cover memberand sometimes includes one or more cross support members continuous withand extending perpendicularly from one side to another side of the covermember. A semi-rigid member sometimes comprises a cellulose composition(e.g., cardboard) that provides a framework for the cover memberallowing for convenient handling by human personnel, and sometimescomprises a material that imparts moisture resistance. The flexiblemember sometimes is fixed to the semi-rigid member, sometimes by anadhesive, sometimes has elastic properties, sometimes forms an air-tightseal if punctured by an air outlet member of an airflow system, andsometimes deforms when positive air pressure is introduced to a cagecomprising the cover. The filter member often is fixed to the semi-rigidmember, sometimes by an adhesive. In some embodiments, the cover membercomprises a multilayered region, or sometimes an entire cover member ismultilayered. One layer often comprises a material that can be puncturedby a tube structure (e.g., the material sometimes is elastic andprovides an air-tight seal around the tube structure), and another layersometimes is constructed from a thicker material. The cover sometimes isa multilayered flexible assembly. In embodiments in which the covercomprises a flexible material, the material sometimes is elastic. Anelastic material utilized sometimes is punctured by a tube structure,such as a needle, and has an elasticity sufficient to form a seal aroundthe tube structure after it is punctured. In some embodiments, the sealis air-tight. An elastic material sometimes has sufficiently elasticityto deform when positive air pressure is delivered to a cage, which canprovide a visual indication that positive airflow is being delivered toa cage. In some embodiments, a cover member includes a region of elasticmaterial that is readily punctured by a tube structure or acicularstructure, such as a needle. In some embodiments, a cover membercomprises a break-away member, that can be adapted to receive a wateringcomponent, feeding component, air supply or air exhaust component, forexample. A cover member sometimes does not comprise an air exhaustconnector and sometimes does not comprise an air inlet connector.Accordingly, in some cover member embodiments: the cover membersometimes is rigid, semi-rigid, or flexible, or comprises a flexibleregion; the cover member sometimes comprises a flexible material and asemi-rigid material, and sometimes a filter; a filter in a cover oftencovers a portion of the surface area of a cover member and not theentire surface area of the cover member; the cover member sometimescomprises a continuously solid surface area and a filter, where thesolid surface area is rigid, semi-rigid, flexible or a combinationthereof; the cover member sometimes comprises a continuously solidsurface area and a filter, where the continuously solid surface area isimperforate and not a grid.

Additional Cage Components

Examples of cage members in addition to a cage base and cover includewatering devices and feeding structures separate from a cage base orcage cover or integrated with the foregoing. These additional membersare referred to herein as “insert members.” A cage insert membersometimes is placed in a cage base or cage cover before a cover issealingly attached to the top of the base. In some embodiments, aninsert member is located near the top of a cage base in proximity to thecover, such as in food trough embodiments described herein. In someembodiments, the inert member defines a top portion of a containmentspace for one or more animals housed in the cage. An insert membersometimes rests on or is positioned by one or more mounts or cradlesextending from an inner surface of one or more sidewall members of acage base (e.g., food tray in FIG. 5 and FIG. 6). In some embodiments,an insert is a substantially flat, planar member, where the surface ofthe insert is parallel to the surface of the cage base bottom member.One or more edges of the insert member often substantially mate,sometimes are substantially flush, sometimes are in close proximity, andsometimes are sealingly contacted with the inner surface of one or moresidewall members. In some embodiments, each edge of the insertsubstantially mates, is substantially flush, is in close proximity, oris sealingly contacted with the inner surface of each correspondingsidewall member. An edge of an insert member is of any thicknessappropriate for the material from which it is constructed for housing ananimal, and sometimes is about 0.010 inches to about 0.080 inches. Aninsert member is constructed of any material suitable for containing ananimal using materials and manufacturing process such as those describedfor manufacturing cage bases, for example.

An example of an insert member is a food tray. A food tray oftencomprises a bottom integrated with four wall members, and optionallycomprises a lid adapted to sealing attach to the food tray. One or moresidewall members and/or the bottom, can include one or more openings orslots that expose food in the feeding structure to a housed animal.Opposing sidewalls sometimes are parallel, non-parallel, curved,elliptical or rhomboid, where two or more of the sidewall members maytaper downwards to a bottom member having a surface area less than thesurface area of the top opening or cover member. Edge and cornerjunctions between the sidewalls and bottom often are curved and have aradius convenient for manufacture and animal feeding. A radius sometimesis selected to minimize abrasions caused by housed animals. A food traymay comprise a flange member surrounding the top edge of the food tray.In some embodiments, the food tray bottom is curved and not flat, and incertain embodiments the food tray is constructed from a plurality ofvertically arranged tubular structures (e.g., wire). A food tray isconstructed of any material suitable for feeding animals, examples ofwhich include but are not limited to: a metal alloy, stainless steel,steel, nickel, nickel alloy, zinc, zinc alloy, a polymer, polypropylene,high-density polyethylene, low-density polyethylene, polyethyleneteraphthalate, polyvinyl chloride, polyethylenefluoroethylene,polystyrene, high-density polystyrene, acrylnitrile butadiene styrenecopolymers and the like, and combinations of the foregoing. In someembodiments, a food tray is constructed from a polymer, such as the samepolymer from which the cover is manufactured, in certain embodiments thefood tray is a metal alloy and in some embodiments the food tray is acombination of a metal structure and a polymer coating. In certainembodiments, the tray is constructed from polyethylene teraphthalate orpolystyrene (e.g., high-density polystyrene). In some embodiments, thefood tray, and sometimes the cage and/or cover, is constructed from asubstantially hard polymer. Such polymers are known and measures ofhardness include Rockwell (e.g., Rockwell M or R), Brinell, Shore, Izod(e.g., Izod impact, notched), Charpy (e.g., Charpy impact, notched) andVickers measures. Substantially hard polymers, as opposed to softerpolymers, may reduce the possibility of gnawing damage caused bycontained animals without increasing or substantially increasingmaterial thickness.

Another example of an insert member is a water supply, which also isreferred to herein as a “reservoir.” Water or another suitable hydratingliquid is emitted to contained animals via the water supply. The watersupply or reservoir, and corresponding reservoir holder or aperture forreceiving a reservoir in a cage component (e.g., cover), is of anygeometry convenient for dispensing water. A reservoir can be abox-shaped structure, sometimes is a substantially cylindricalstructure, and sometimes is a substantially cylindrical structure withgently tapered side walls (slightly conical) and a chamfer. A reservoirsometimes is geometrically configured to reduce the potential ofabrasions caused by housed animals (e.g., reduce abrasions caused byanimals gnawing on the watering structure), and in some embodiments, areservoir comprises rounded corners (e.g., a rounded junction between abottom edge and a sidewall member edge) and/or edges (e.g., roundedjunction between two sidewall member edges). Rounded corner radiuses aredescribed herein. A reservoir sometimes is adapted to mate with asealingly attachable lid or cap located in a convenient location of thebottle (e.g., the top or bottom), such as a screw-on lid or snap on lid,for example, such that the reservoir can be filled with water and thensealed with the lid. Accordingly, a reservoir often includes male orfemale threads adapted to receive threads from a screw-on lid or afitting for a snap-on lid. A portion of the reservoir exposed to theinside of a cage (e.g., the bottom of the reservoir, cap or lid) oftenincludes a small aperture that can retain water by surface tension untilcontacted by an animal. A side wall region of the reservoir may bechamfered and sometimes can mate with a corresponding chamfer in areceptacle of the cover. Such a chamfer can function as a key thatensures alignment of the reservoir in the cover. A step in a radius ofthe aperture also may generate an interference fit with the reservoirreceptacle, ensuring a tight seal between the reservoir and the coverand thereby reducing and substantially preventing air leakage. Areservoir is constructed of any material suitable for containing a fluidfor hydrating animals (e.g., water) including but not limited to:polypropylene, high-density polyethylene, low-density polyethylene,polyethylene teraphthalate, polyvinyl chloride,polyethylenefluoroethylene, acrylnitrile butadiene styrene copolymers,cellulose, cellulose lined with a polymer or metallic foil, and thelike.

For embodiments in which a cover comprises a water reservoir holder, thereservoir holder sometimes is substantially cylindrical with slightlytapered sidewalls and a chamber located in the side and bottom. Such ageometry of the holder can key a similarly shaped reservoir, where thechamfers of the holder and the reservoir mate. Such holders ofteninclude an aperture, often in the chamfer region, adapted to receive anemitter from the reservoir, such that the emitter is accessible to ahoused animal. Such holders often are adapted to receive a reservoirthat includes a step in the radius such that the top portion of thereservoir has a larger diameter than the lower portion, which providesan interference fit with the inner wall of the holder and asubstantially air tight fit.

In some embodiments, an emitter contains a valve sometimes located inthe emitter and sometimes located at the junction of the emitter and thereservoir. In some embodiments, the emitter contains no valve. A quickrelease coupling sometimes connects the emitter to the reservoir. Incertain embodiments, the emitter is conical with the larger crosssectional area connected to the reservoir and a small aperture on theopposite end accessible to a housed animal. In such embodiments, theaperture is sized to retain water in the reservoir by surface tensionand to emit water when contacted by a housed animal. In certainembodiments, provided is a water bottle for use in conjunction with acover, which comprises a cap having an aperture that retains water viathe inherent surface tension of water within the cap face, the latter ofwhich is defined by a flat surface. In the latter embodiments, the capeface is not conical and does not include a projection.

In certain embodiments the water supply comprises an aperture oremitter, and water sometimes is retained at the aperture or emitter bysurface tension. The aperture often is located in a cap in connectionwith the water supply. The cap sometimes is reversibly attached to thewater supply, or may be integrated with the water supply. In someembodiments, the cap comprises a removable barrier over the aperture,which sometimes is an adhesive tab that prevents water spillage duringshipping. The removable barrier can be removed by a user before use. Thecap sometimes comprises a planar or substantially planar surface. Theplanar surface often comprises a centered aperture, and often does notcomprise a raised member, and may contain an emitter that retains waterby surface tension. The water supply sometimes is a water bottle, whichcan be mounted in a receptacle in the cover.

Other insert members may be in association with a cage assembly, such asa shelter structure, bedding material, and/or a sub-floor, for example.A shelter structure is of any shape or geometry that allows an animal toenter the structure and become covered or partially covered by thestructure. Any convenient structure for housing animals can be used, andin some embodiments, a shelter is a perforated pipe structure. Anexample of a combined feeding and shelter structure is described in U.S.Pat. No. 6,571,738.

A bedding material often is placed in a cage. Any bedding materialsuitable for housing animals can be used, such as wood chips arenewspaper, for example. In some embodiments, a removable sub-floorsometimes is positioned in association with a cage base. A sub-floor isconstructed from any material and is of a geometry that allowsfoodstuffs, liquid emissions and/or solid emissions from a housed animalto pass through the sub-floor to the cage base bottom member, and insome embodiments, a sub-floor member or a portion thereof is reticulatedor perforated (e.g., http address www.ssponline.com/bed.html). Ascavenging substance described previously may be placed under thesub-floor in certain embodiments.

In some embodiments, an insert member comprises two or more connectedplanar members, where each planar member has a surface parallel to asurface of another planar member and the bottom surface of one planarmember is elevated with respect to the top surface of another planarmember. In the latter embodiments, each planar member is connected by ariser member, where a surface of the riser member sometimes isperpendicular to surfaces of the connected planar members and sometimesconnects the planar members at a non-perpendicular angle (e.g., about 10degrees to about 95 degrees). The planar members and one or more risermembers often are contiguous, often with seamless junctions. An insertmember often is manufactured by a process that renders a unit having noseams or disconnections between the planar and riser members. An insertmember sometimes comprises an aperture or a combination of an apertureand a recessed flange adapted to receive a component useful for meetingrequirements of a housed animal, such as a feeding structure, wateringstructure and/or shelter structure, for example. An insert membersometimes comprises one or a plurality of sidewall members (e.g., two,three or four sidewall members) extending downwards into the interior ofa cage base member also adapted to support a component useful formeeting requirements of a housed animal. The outer surface of a sidewallmember often is perpendicular to the bottom surface of an insert planarmember from which it extends and often are contiguous with the bottomsurface of an insert member. In some embodiments, a bottom edge of asidewall member is not parallel to the bottom surface of an insertplanar member, and sometimes a side edge of a sidewall member is notperpendicular to the bottom surface of an insert planar member. Aninsert may comprise one or more apertures allowing air to enter and/orexit the cage. In some embodiments, the one or more apertures, sometimesreferred to as “vents,” diffuse air entering a cage at the top surfaceof the insert. In certain embodiments, one or more vents are in thefront portion of the insert so that air flows from the front of the cageto the back of the cage, sometimes by laminar flow (e.g., downward nearthe front to upward near the rear). The apertures are of any geometryallowing for air flow, such as circular, rectangular, square, rhombusand/or reticulated, for example. An insert member often is not connectedto a filter. An insert member may comprise one or more openings,apertures or recesses for receiving other structures, and sometimes isintegrated with one or more other structures. Such structures sometimesare utilized for feeding, watering and/or sheltering animals housed inthe cage. Two or more of such structures sometimes are integral, such asan integrated feeding/shelter structure. Where an insert member includesan opening, aperture or recess for receiving another structure, theother structure often is in removable association with the insert, andin some embodiments, the other structure is sealingly mated with theinsert member.

Cage and Cage Component Embodiments

In accordance with the foregoing descriptions of cages and cagecomponents, examples of specific embodiments are described hereafter. Insome embodiments, provided herein are animal containment cagescomprising a wall or walls and a bottom, where the cage is constructedfrom a polymer, and the thickness of each wall is about 0.01 inches toabout 0.08 inches. Examples of suitable polymers are described above. Incertain embodiments, the thickness of the bottom is about 0.01 inches toabout 0.08 inches. The wall or walls and bottom often are of asubstantially uniform thickness. The thickness of the wall or walls orbottom sometimes is about 0.01 inches to about 0.05 inches, at times isabout 0.02 inches to about 0.06 inches, and can be about 0.02 inches toabout 0.03 inches. In some embodiments, the cage is semi-rigid and canflex. The single-use cages provided herein generally are flexible orsemi-rigid in comparison to multiple-use plastic cages (e.g., U.S. Pat.No. 5,894,816). The cages provided herein can weigh about 250 grams orless or about 225 grams or less, and they sometimes weigh about 150grams or less or 125 grams or less (e.g., about 115 grams) due to therelatively thin plastic walls and bottom. Sidewalls of a cage often arecoextensive with the bottom. In certain embodiments the cage sometimesincludes three walls (e.g., the cage bottom having a triangle orgenerally pie-slice geometry) or is cylindrical (e.g., the cage bottomis circular or oval and coextensive with a wall). A cage often comprisesfour walls, and the interior surface of the bottom sometimes is asquare, rectangular, rhombus, trapezoid or parallelogram. In certainembodiments, at least one set of opposing walls taper inwards towardsthe cage bottom, and often all walls taper inwards towards the bottom.One or more walls, and sometimes all walls, often are at an angle ofgreater than 90 degrees with respect to the bottom. In the latterembodiments, the angle sometimes is about 91 degrees to about 105degrees, and can be about 92 degrees to about 98 degrees, or about 95degrees.

In certain embodiments, one or more of the wall or walls, bottom andcover comprise an indent or boss that increases cage rigidity. Incertain embodiments, a wall comprises an indent extending from thejunction of the bottom and the wall. A cage base often has no aperture.A cage base comprises in certain embodiments an indent on each of twosidewalls and a mount in connection with each indent in which a feedingtray may be or is nested (e.g., a food tray cradle). A cage base oftencomprises a flange, and optional lip, surrounding the top edge of thebase capable of an interference fit with a corresponding structure in acage cover.

In certain embodiments, one or more or all edges of an indent or bossare rounded edges. Rounded edges sometimes are defined by a radius ofabout 0.25 inches or greater, and the radius can be about 0.30 inches orgreater or about 0.25 inches to about 0.50 inches. In certainembodiments, one or more wall to wall junctions or wall to bottomjunctions are rounded junctions. The rounded junctions sometimes aredefined by a radius of about 0.25 inches or greater, and the radius canbe about 0.30 inches or greater or about 0.25 inches to about 0.50inches.

In certain embodiments, one or more junctions between the bottom and twowalls comprise two or more corners, and sometimes the one or morejunctions comprise three or more corners or three corners. Thesefeatures can improve impact resistance of relatively thin-walled cages.In some embodiments, corners of the cage are rounded corners, and therounded corners sometimes are defined by a radius of about 0.25 inchesor greater, a radius of about 0.30 inches or greater, or a radius ofabout 0.25 inches to about 0.50 inches.

Certain embodiments are directed to an animal containment cagecomprising a wall or walls and a bottom, where the wall or walls andbottom are constructed from a polymer, the thickness of each wall isabout 0.01 inches to about 0.08 inches, wall junction edges and cornersare rounded and have a radius of about 0.25 inches or greater, and oneor more of the walls and bottom comprise one or more bosses or indents.The radius sometimes is about 0.30 inches or greater. Other featuresdescribed herein with regard to cage bases are applicable to suchembodiments.

A cage base member generally does not comprise an air filter, and a cagebase often comprises a continuously solid and imperforate bottom andsidewalls. While a cage generally does not comprises an air exhaust orair inlet aperture, in some embodiments a cage base may comprise one ormore apertures in one or more sidewalls or bottom, often the rearsidewall, adapted to receive or connect to a structure that removes orsupplies air, water, food or other material to the cage, such as an airsupply component, air exhaust component, and/or water supply component.In the latter embodiments, one or more apertures in a sidewall sometimesare in connection with a seal (e.g., an elastic ring seal) integratedwith the cage base or applied to it by a user. In some embodiments, therear wall of a cage base includes one or more apertures adapted toreceive or connect to an air supply component, air exhaust component,and/or central water supply component. In some embodiments a base unitmay comprise a break-away member that can expose an aperture forreceiving a component such as a sensing probe, water delivery structureor air delivery structure, for example. A break-away member, sometimesreferred to as a “punch out” member, sometimes breaks away entirely andsometimes remains attached to the cage by a portion after being broken.In certain embodiments, a cage base may comprise a filter member and oneor more optional exhaust ports.

A cage provided herein often is a single-use cage, and sometimes is incombination with a rack, an airflow unit, an airflow controller or acombination thereof. A cage described herein can comprise one or moreanimals. The animal sometimes is transgenic, immunodeficient, inbred,contains one or more xenografts and/or lacks one or more functionalgenes (knock-out animal). The animal often is a rodent, such as a rodentselected from the group consisting of mice, rats, hamsters, gerbils,guinea pigs, chinchillas and rabbits, for example. A contained mousesometimes is a nude mouse or a severe combined immune deficiency (SCID)mouse.

Specific embodiments of cage bases and cage systems are illustrated inFIGS. 1, 2, 3, 4, 5, 6, 7A, 7B, 8, 9, 10 and 11. FIG. 1 is a topisometric view of an assembled cage embodiment showing a generaloverview from the upperfront perspective. Cage base (101) is mated to acage cover (102), the latter of which is in association with a waterbottle (105) and includes an air inlet port (146) and an air exhaustport (145). Filter media may be positioned beneath a raised, bossedsurface (119) comprising apertures (119A). An optional cage card holder(109) is bonded to cage base (101), often via ultrasonic welding oradhesive. Adhesive or welds can be applied to surfaces (108) of the cardholder (109) to affix it to the base (101).

FIG. 2 is an exploded view of the cage assembly shown in FIG. 1, andprovides further detail of a water bottle cap (106) and food trough(103). Filter media (104) may be removable and often is permanentlyaffixed. In embodiments that comprise a filter shield (107), the shieldoften is attached to the bottom surface of cover (102). Filter media(104) may be affixed in the cage cover between the bottom side of bossedsurface (119) of the cover and the top side of bossed surface (107A) ofa filter shield (107). Filter media (104) also may be affixed in thecage cover between channel (147) and bossed surface (107B). The filtershield protects the filter paper from chewing by animal residents. Incertain embodiments, filter shield (107) is permanently adhered aroundits perimeter to cover (102) with adhesive. An alternative to adhesiveis ultrasonic welding or heat sealing of the filter shield to the bottomsurface of the cover (102). The sealed border can serve as a barrier toair leakage, and in certain embodiments, all or substantially allairflow passes through the filter paper. The filter paper often allowsair to pass through and filters particles, and in some embodiments thefilter paper is replaced with a non-breathable medium to prevent airfrom leaving the cage in the region to which the medium is affixed. Inthe latter embodiments, air can be evacuated from an exhaust port (145)and not from array of apertures (119A).

FIG. 3 is a cross sectional view taken at the center of the water bottlein an embodiment. Radius (102) is sufficiently large to prevent chewingby an animal resident, and often is about 0.25 inches or greater,sometimes about 0.30 inches or greater, and sometimes is about 0.25inches to about 0.50 inches. A small hole in the surface containingradius (102) allows passage of an optional nipple of screw cap (106) orallows access to a hole in a screw cap having a substantially flatsurface. The hole is small enough to prevent animal residents (e.g.,mice) from escaping when the water bottle is filled or replaced. Screwcap (106) may be alternatively substituted with a press-on cap or abonded foil lid, thereby obviating mating threads in water bottle (105).Screw cap (106) has a substantially flat surface in some embodiments.The curved top surface of water bottle (105) provides strength andstability when rested upside down. Junction (110) between the waterbottle and the top cover forms a seal (e.g., a tight fit seal) toprevent unwanted air from passing in or out of this region.

FIG. 4 is a cross sectional view taken through the food tray (103) of anembodiment. This view shows the food tray resting on tray indent (115).The top cover (102) prevents the food tray from being lifted in theupwards direction by animal residents (e.g., mice) while eating due tothe proximity of the top of the food trough with the cover (129). Slots(138) allow animal residents to access food in the trough from below.Additional material (116) is located around the perimeter of the slotspresent rounded edges through which animal residents are less likely tochew than harder edges. Branding and logos may be affixed to theunderside of raised area (118).

FIG. 5 is a cross sectional view taken through the end of the food trayof an embodiment. Area (129) shows the edge of food tray (103) isprotected by the top cover so that animal residents cannot chew on theedge. Food tray (103) sometimes is constructed from metal to minimizeeffects of chewing or the user wishes to re-use this part. FIG. 6 is across sectional view taken through the end of the food tray in anotherembodiment. FIG. 6 shows an orientation of the trough engaged with thecage base. This view shows a configuration of the food trough resting ona mount formed within an indent in a cage base. A contact point betweenthe cage cover, cage base and feeding trough (129) shows the edge offlange (103A) is protected by the top cover thereby protecting theflange from chewing by animal residents. Food tray (103) can beconstructed of any suitable material for animal containment, such as apolymer (e.g., a substantially hard polymer) in single-use embodiments,or stainless steel if the user wishes to minimize chewing by animalresidents or wishes to re-use this part. Surfaces (103B) and (103C) ofthe food trough increase rigidity of the structure and reduce troughsfrom adhering to one another one nested. In certain embodiments,apertures in the food trough are surrounded by thicker material than thematerial thickness of the trough sides and bottom, and the thickermaterial often forms ribs around the apertures. Such ribs can reduce anychewing damage to the food trough caused by an animal resident.

FIG. 7A is a cross sectional view taken through the middle of the cage.This view shows filter media (104) sandwiched between cover (102) andfilter shield (107). An array of small holes (107C and 119A), sometimeshaving a diameter of about 0.125 inches, allow air to exit the cage.Holes (107C) also are sized to prevent animal residents from gnawing onthe edges of the holes. Raised surface (119) allows air to diffusebefore exiting or entering the filter, thereby facilitating airflowthrough the cage. Raised surface (107A) and raised surface (107B)prevent animal residents from accessing and gnawing on filter medium(104). Filter medium (104) is not allowed to droop due to ribs along theX axis placed between the arrays of holes (119A). Filter media also maybe located directly below exhaust nozzle (145) and airflow channel(147). This geometry ensures air exiting the cage is filtered to preventdust and debris from clogging downstream plumbing. The S-shaped flowchannel (147) shown in FIG. 2 prevents filter media from deforming andadhering to the top surface of the channel, a feature which maintainsairflow and decreases the possibility of airflow blockages by a deformedfilter medium. Filter (104) generally is single use and is replaced eachtime the cover and cage is replaced. FIG. 7B is an expanded view of theencircled region of FIG. 7B, and shows raised surface (107A) and raisedsurface (107B) in the filter shield (107), raised surface (119) in thecover (102), filter media (104) and air exhaust port (145).

FIG. 8 is a cross sectional view taken through the middle of a foodtrough embodiment. Air enters the cage through aperture (130) and exitsthe cage through aperture (131). The figure shows airflow streamlinescaused by food trough (103). Front to rear or rear to front airflowprovides advantages of minimizing recirculation and efficiently purgingcage air from the cage. Food trough (103) acts as a baffle to direct airinto the bedding material where the air can efficiently removecontaminants from the cage.

FIG. 9A and FIG. 9B show a top view of a cage base embodiment. This viewshows food trough cradles or indents (115). Mating surface (112) isadapted to receive a top cover. Tabs (117) are useful for separating thecover (element 102 in FIG. 1) from the cage base (101). Radius (130)prevents gnawing on the cage, and often is about 0.25 inches or greater,sometimes about 0.30 inches or greater, and sometimes is about 0.25inches to about 0.50 inches.

FIG. 10A and FIG. 10B show a side view of a cage base embodiment. Shownare front member (129) and side members (113). Radius (111) is locatedbetween the bottom (133) and the sides. Radius (111A) is a roundedcorner effectively having one edge, and radius (111B) is effectivelydivided into three corners. Surface (135) receives a food tray andindent (136) aids in positioning the food tray and the food tray andprevents nested cages from significantly adhering as its short length isvertical.

FIG. 11 is a section view showing a flange/lip portion of a cage base(101) positioned to mate with a corresponding portion of a cover member(102) by a snap interference fit. As the top cover is lowered onto thecage base portions of each deflects as cover lip member (27) is matedwith cage lip member (22). When fully mated, cover lip member (27) snapsinto its final position substantially adjacent to cage lip member (23)thereby forming a seal. Indent (20) can prevent cage bases fromsubstantially adhering to one another when nested. Cage flange member(21) substantially mates with cover flange member (24) to provide aseal. In some embodiments, a cage base does not include member (23),members (23) and (12), members (23), (12) and (21), or members (23),(12), (21) and (20). In certain embodiments, a cage cover does notinclude member (27), members (27) and (26), or members (27), (26) and(25).

In certain embodiments, provided is an animal containment cage coverconstructed from a polymer having a thickness of about 0.01 inches toabout 0.08 inches. The thickness of the cover sometimes is about 0.01inches to about 0.05 inches, and can be about 0.02 inches to about 0.06inches or about 0.02 inches to about 0.03 inches. The cover often issemi-rigid and relatively flexible due to its relative thinness. A coversometimes weighs about 175 grams or less or 150 grams or less, and oftenweighs about 125 grams or less or about 100 grams or less (e.g., about75 grams). In certain embodiments, a cover comprises one or morefilters, sometimes weighing about 5 grams (each or in total), and one ormore optional filter shields, sometimes weighing about 25 grams or less.The cover sometimes is constructed from the same polymer as the cagebase (e.g., a cover and base sometimes are constructed from PET),although the cover can be constructed from one polymer and cage base canbe constructed from another polymer (e.g., a cage base may beconstructed from a polystyrene and a cage cover may be constructed fromlow density polyethylene). The cover sometimes is in sealing connectionwith a cage base.

Also provided herein are animal containment cage covers that comprise anair inlet aperture and an air exit aperture. The air inlet sometimes islocated substantially at one end of the cover and the air exit sometimesis located substantially at the other end. A cover sometimes comprisesan array of air exit apertures. In some embodiments, a cover comprisesan air supply connector comprising the air inlet aperture, and sometimesa cover comprises an air exhaust connector comprising the air exitaperture, or a combination thereof. These apertures sometimes arelocated on a bossed region of the cover, and two or more of these may belocated on the same or different bossed region (e.g., the air inletaperture(s) may be located one boss and the air exit aperture(s) may belocated on another boss). One or more of such connectors can be convexwith respect to the outer surface of the cover, and can be conical. Forsuch embodiments pertaining to air inlet connectors, air can expand asit flows through air supply connector into the cage, which can reducethe temperature of the air and offset thermal load from an animal.

In certain embodiments, a cover comprises a channel in connection withan air exhaust connector and/or air inlet connector. The length of thechannel often extends across the cage width (e.g., across the Y axis,FIG. 1), and sometimes extends part of the length of the cover,sometimes the entire length of the cover or sometimes substantially theentire length of the channel (e.g., terminates within about 2 to 3inches independently from either edge of the cover). The channel lengthsometimes is non-linear, and sometimes it is sinusoidal. A channel cancomprise apertures on the bottom side of the cover, and the aperturesmay be distributed across the length of the channel (e.g., evenlydistributed or unevenly distributed), which can facilitate uniform airdistribution within the cage. In certain embodiments, the channel in thecover is open along the bottom of its length, and sometimes the channelis formed by a channel in the cover and another channel in a filtershield joined to the underside of the cover. The channel in the filtershield in such embodiments often comprises apertures on the bottom sideof the filter shield, which sometimes are distributed along the channellength. The channel in the filter shield can be of any geometry, and incertain embodiments, the channel length in the filter shield is linear.In some embodiments, the air inlet connector and channel connected to itis located substantially at one end of the cover and the air exhaustconnector and channel connected to it is located substantially at theother end.

A cover comprises one or more filters (e.g., filter paper(s)) in someembodiments. A filter or combination of filters sometimes are adhered toor located in proximity to (e.g., located under) (a) a bossed surface ofthe cover, (b) an air aperture in the cover (c) an air inlet aperture,(d) an air exhaust aperture, (e) an array of air exhaust apertures, (f)an air inlet connector, (g) an air exhaust connector, (h) a filtershield surface, (h) a bossed surface of a filter shield, (i) a channelsurface of a filter shield, (j) cover surface, (k) a channel surface ofa cover, or combinations of the foregoing. A surface of the filter(e.g., the surface closest to a surface of a cover or shield member)sometimes is separated from the cover or shield surface member by about0.05 inches to about one inch, sometimes about 0.1 inches to about 0.2inches, and sometimes about 0.125 inches, which can facilitate airflowand/or reduce the possibility of filter damage caused by a containedanimal. Thus, for embodiments in which the filter is under a boss of thecover, the surface of the filter closest to the bossed surface of thecover sometimes is separated from the bossed surface by about 0.05inches to about one inch, sometimes about 0.1 inches to about 0.2inches, and sometimes is separated by about 0.125 inches. In certainembodiments, the filter is located between the bossed surface of thecover and a filter shield in connection with the underside of the cover.The shield can be connected to the cover in any convenient manner, suchas by an adhesive or a weld or welds, for example. The shield oftencomprises a bossed surface, which sometimes is located under, andoptionally aligned with, the bossed surface of the cover, and the filteroften is located between the bossed surface of the cover and the bossedsurface of the shield. In the latter embodiments, the surface of thefilter closest to the bossed surface of the shield is separated from thebossed surface of the shield by about 0.05 inches to about one inch(e.g., about 0.1 inches to about 0.2 inches or about 0.125 inches). Theshield in some embodiments contains a channel, and sometimes contains achannel and a separate bossed surface having a larger surface area. Anopen channel of a shield often is located under an open channel of thecover, thereby forming a complete channel between the two members (e.g.,FIG. 2), and a filter sometimes is located between the channel of theshield and the channel of the cover. In such embodiments, the channeland bossed region of the filter shield and cover often are separated bya barrier (e.g., adhesive or weld) to prevent or substantially reduceairflow bypass. In some embodiments, the channel and bossed surface maybe located on separate shield parts affixed to the underside of thecover, and separate filters can be located within each shield piece. Theshield often comprises one or more apertures, but may contain noapertures in certain embodiments. In certain embodiments, the bossedsurface of a shield comprises apertures, sometimes an array of aperturesoften aligned with apertures in a bossed region of the cover. A channelin a shield sometimes comprises one or more apertures, and sometimes anarray of apertures spaced across the length of the channel. Apertures inthe cover and shield often are of a small enough diameter tosubstantially reduce or prevent gnawing by animal residents and allowfor airflow. Apertures sometimes are of a maximum diameter of about 0.1to about 0.2 inches and sometimes a diameter of about 0.125 inches. Insome embodiments, the bossed surface of the shield or a channel in theshield comprises no apertures. In some embodiments, the cover comprisesno filter, and sometimes a cover comprises a non-porous membrane thatsubstantially blocks airflow.

Provided also are cages and other animal containment system componentsdescribed herein in an elevated biosafety level environment, and uses ofthe such components and systems in elevated biosafety levelenvironments. Elevated biosafety level environments include environmentsin which one or more risk components potentially harmful or harmful topersonnel, such as pathogens, toxins or controlled substances, areutilized. Thus, provided is a containment system or components describedherein in combination with an animal contacted with a risk component.Elevated biosafety level environments can include Biosafety Level 2, 3or 4 environments. Biosafety Level 1 is suitable for work involvingwell-characterized agents not known to cause disease in healthy adulthumans, and of minimal potential hazard to laboratory personnel and theenvironment. Biosafety Level 2 is similar to Level 1 and is suitable forwork involving agents of moderate potential hazard to personnel and theenvironment. Biosafety Level 3 is applicable to clinical, diagnostic,teaching, research, or production facilities in which work is done withindigenous or exotic agents which may cause serious or potentiallylethal disease as a result of exposure by the inhalation route.Biosafety Level 4 is required for work with dangerous and exotic agentswhich pose a high individual risk of aerosol-transmitted laboratoryinfections and life-threatening disease. In higher biosafetyembodiments, one or more or all apertures of the cages often are ineffective connection with one or more filters, and airflow componentssometimes are in effective connection with one or more filters. Thus,one or more of the following containment components may be in effectiveconnection with one or more filters (i.e., filtration occurs by director indirect connection): air exhaust aperture array, air exhaustconnector, air supply connector, air supply aperture, air supply blowerand air exhaust blower. In certain embodiments, one or more of thesecontainment components are in effective connection with an airflow block(e.g., a non-porous membrane). For example, an array of exhaustapertures may be in connection with an airflow block, and an air inletconnector and air exhaust connector may be in effective connection withone or more filters.

In certain embodiments, provided are animal containment cage coversconstructed from a polymer, comprising an air inlet aperture, an airexhaust aperture, a first filter in effective connection with the airinlet aperture (e.g., filters air entering the air inlet aperture) and asecond filter in effective connection with the exhaust aperture (e.g.,filters air exiting the exhaust aperture). In some embodiments, thefirst filter and the second filter and separate, and in otherembodiments, the first filter and the second filter are coextensive orare regions of one filter. Each aperture sometimes is part of aconnector. A connector often is convex and sometimes is conical, and inembodiments directed to air inlet connectors, air expands after itpasses from the air inlet aperture through the connector. In someembodiments, the air exhaust aperture is part of an array of apertures.Such covers sometimes are in combination with a cage base having a wallor walls and a bottom, and sometimes in combination with othercomponents, such as a rack, airflow unit, airflow controller, orcombination thereof. Such cover embodiments can be utilized in higherbiosafety level environments.

Certain embodiments are directed to an animal containment cagecomprising a cover and a base having a wall or walls and a bottom, wherethe walls, bottom and cover are constructed from a polymer, and thecover and the base attach by an interference fit. In some embodiments,the interference fit is a snap interference fit or a frictioninterference fit. In certain embodiments, the base comprises a firstflange, the cover comprises a second flange corresponding to the firstflange and the interference fit results from deflection of the firstflange and the second flange. The cover and base often sealingly attachand often reversibly attach. In certain embodiments, an edge of thecover is coextensive with an edge of the base (e.g., clamshellorientation), and alternatively, the cover and the base sometimes areseparate.

Also provided are animal containment cage covers that comprise anintegrated water supply receptacle. This receptacle in the coversometimes comprises a water supply or is joined with a water supply. Thecover receptacle sometimes is joined to a central watering system. Thereceptacle in the cover and water supply often fit with one another viaan interference fit, where the interference fit sometimes is a frictionfit and sometimes is a snap fit. The interference fit often provides anair-tight seal or substantially air-tight seal. The receptacle sometimescomprises a chamfer region and an aperture in the chamfer region, intowhich a water supply has a corresponding chamfer that mates with thechamfer of the receptacle. In certain embodiments, the receptacle andwater supply are cylindrical or substantially cylindrical and the radiusof the top portion of a water supply that inserts into the receptacle islarger than the bottom portion. The aperture often receives or reveals awater emitter connected to the water supply.

Provided also herein is an animal containment cage comprising a wall orwalls, a bottom and a cover, where the walls, bottom and cover areconstructed from a polymer, and the thickness of each wall is about 0.01inches to about 0.08 inches. As described in embodiments above, thecover can be coextensive with a wall edge (e.g., clamshell), or thecover can be separate from the wall or walls and bottom of the cage. Thethickness of the cover can be about 0.01 inches to about 0.08 inches,and the cover can be constructed from the same or a different polymer asthe walls and bottom. The cover can comprise one or more air supplyapertures, one or more air supply connectors, one or more air exhaustapertures, and/or one or more air exhaust connectors. The top surface ofthe one or more connectors often comprises an aperture. The connectorsoften are convex with respect to the outer surface of the cover, and canbe protrusions that do not extend into the interior of the cage when thecover is attached. A sidewall of one or more connectors sometimes isconical.

Specific embodiments of cage covers are illustrated in FIGS. 12, 13, 14and 15, in addition to depictions in previous Figures. FIG. 12 shows afront isometric view of a cage top embodiment. Receptacle (142) receivesa water bottle. Boss (140) is raised above the mating surface thatengages the cage base to achieve the minimum 5 inch ALAS requirement.Boss (140) also strengthens the cage top near the water bottle. Boss(143) is raised to achieve a cage height of about five inches. An arrayof exhaust holes (119A) in an raised embossed surface (119) allowsufficient airflow through the cage. Tab (144) can aid a user inseparating lid (102) from a cage base (101). Tab (144) can be used inconjunction with tab (117) of the cage base to separate the parts by theuser applying his or her thumb and index finger. The conical shape ofthe inlet conical receptacle (146) interfaces with a conical section inthe rack shelf (e.g., element 220, e.g., FIG. 34) to form a seal.Conical receptacle (145) often serves as an exhaust port when mated witha conical exhaust connector.

FIG. 13 shows a side view of a top cover embodiment. Vertical shoulder(148) can form a seal with water bottle (105). The short vertical wall(148) prevents cage lids (102) from nesting too tightly andsignificantly adhering to one another.

FIG. 14 shows a top view of a cover embodiment. Conical receptacles(145) and (146) can serve as alignment features to correct for amis-inserted cage assembly. Depression of the array of holes (119) belowthe top surface of the boss separate affixed filter paper from the arrayof holes. This separation prevents animal residents from chewing onaffixed filter paper. Water bottle cap (106) passes through aperture(141), the latter of which is small enough that an animal residentcannot escape if the water bottle is not present. Cones (145) and (146)can serve as alignment features to correct for a cage assemblymis-inserted into a rack. Raised surface (119) is embossed and includesan array of holes (119A). The raised surface stands the filter paper offthe array of holes, which allows air to diffuse prior to exiting thecage. Water bottle cap (e.g., element 106 in FIG. 2) may pass throughaperture (141).

FIG. 15 is a bottom view of the top cover and an affixed filter shield.Holes (107C) are distributed across the Y-axis of raised surface (107B).As a result of this distribution, air is uniformly drawn into the flowchannel before it exits exhaust cone (145), and improves airflow on theside of the cage opposite the intake cone (146) and exhaust cone (145).The array of holes (107C) in raised portion (107A) of filter shield(107) are aligned with the holes in the top cover (119A). All holes inthe filter shield are sized (e.g., less than or equal to about 0.125″)to allow airflow and prevent chewing by eliminating or substantiallyreducing access of contained animals to the filter paper.

In certain embodiments, provided are animal containment cage food trayscomprising walls, a bottom and apertures, where the walls and bottom areconstructed from a polymer. The trays sometimes are injection molded,and apertures sometimes are surrounded by a rib thicker than the wallsand bottom. A tray sometimes comprises a flange coextensive with the topedge of two or more walls, and sometimes comprises one or more tabssharing an edge with a sidewall. Such tabs can fill gaps that would bepresent when the food tray joins with cradles in a cage but for thetabs. In certain embodiments, one or more sidewalls contain one or morebevels. Any suitable polymer can be utilized to construct a food tray(e.g., polymers described herein for cage bases and covers), and incertain embodiments, a tray is constructed from a substantially hardpolymer such as polystyrene (e.g., high density polystyrene). Thethickness of the tray walls and bottom often is about 0.03 inches toabout 0.05 inches. In certain embodiments, one or more junctions at oneor more walls and the bottom of the feeding tray are rounded junctions.The rounded junctions sometimes are defined by a radius of about 0.25inches or greater, and the radius can be about 0.30 inches or greater orabout 0.25 inches to about 0.50 inches. A feeding tray sometimes is incombination with a cage, and often is positioned by one or more mountsin one or more walls of the cage. The feeding tray can direct airentering the cage from the cover towards the cage bottom in someembodiments, and can function as a baffle that directs air entering thecage from the cover towards the cage bottom. In such embodiments, airflows into the cage from one location of the cover, flows under thefeeding tray and exhausts through another location of the cover.

FIG. 16, FIG. 17A and FIG. 17B show specific food tray embodiments. FIG.16 is an isometric view of a food trough embodiment. The figureillustrates perforate slots in the food trough that allow access tofood. The entire perimeter of slots (138) have an increased thickness orrib to slow or prevent chewing on the food tray. Rib (149) also slows orprevents chewing on the food tray. Tabs (139) allow the food tray torest in the indent of cage base (101). These tabs prevent the food trayfrom rocking in the cradle of the cage base (101). Strengthening ribs(134) support the tabs. FIG. 17A is a top view of the food troughembodiment. FIG. 17B is a side view of a food trough embodiment.Horizontal surface (138) allows for the food trough to rest on a cageindent. Rib (149) of increased thickness slows or prevents chewing onthe edge near the top cover (102). Ribs (134) increase stiffness of thefood tray.

In certain embodiments, a cover or cage comprises a water supply or isjoined with a water supply. A water supply provides a hydrating liquidsuitable for containing animals, which often is water. The cover or cagesometimes is joined to a central watering system. The water supplysometimes connects to the cage cover by an interference fit, which canbe a friction fit or snap fit. The water supply generally comprises anaperture, and water often is retained at the aperture by surfacetension. The aperture may be located in a cap in connection with thewater supply. The cap can comprise a removable barrier over theaperture, and the cap sometimes comprises a substantially planar surfacethat generally does not comprise a raised member. The cap sometimes isreversibly attached to the water supply. The water supply sometimes is awater bottle that may be mounted in a receptacle in the cover. A coveror cage sometimes comprises an integrated water supply receptacle, andthe receptacle may comprise a chamfer region and an aperture in thechamfer region. A water supply inserted into the receptacle may comprisea chamfer that mates with a corresponding chamfer of the holder. Thereceptacle and water supply can be cylindrical or substantiallycylindrical and the radius of the top portion of a water supply thatinserts into the receptacle is larger than the bottom portion. Thereceptacle may comprise an aperture that receives or reveals a wateremitter connected to the water supply.

FIG. 18A and FIG. 18B show water bottle embodiments. FIG. 18A is anisometric view of a water bottle embodiment. Tapered shoulder (155)seals with the vertical surface of the top cover to form a seal. Taperedwall (105) allows for increased water capacity. FIG. 18B is a front viewof the water bottle embodiment. Surface (157) is slightly taperedconfers added strength to the neck region of the bottle. Tapered wall(158) allows for increased water capacity.

Nested Cage Components

A cage component can be inserted into another like cage component andseveral components can be stacked, which is referred to herein as“nesting.” Nesting cage components significantly reduces the volume ofmultiple cage components as compared to the same number of un-nestedmembers, which is advantageous for shipping, storage before housing ananimal, and storage after housing an animal, for example. Any convenientnumber of like components can be nested, including, but not limited to,10 or more, 20 or more, 30 or more, 40 or more, 50 or more, 60 or more,70 or more, 80 or more, 90 or more or 100 or more like components. Thedegree or efficiency of nesting sometimes can be expressed in terms of apercentage, which is the height or volume of the nested component withinanother like component containing it, relative to the overall height orvolume of the nested component. Thus, the term “80% nested” indicates80% of the volume or height of a nested cage member, for example, iscontained within the member in which it is inserted. When stacked, cagebases provided herein often are 75% or more nested, sometimes 80% ormore or 85% or more nested, and sometimes about 90% to about 95% nested.Cage covers (described in greater detail hereafter) often are 75% ormore nested, and sometimes are about 80% to about 85% nested when theyinclude an integrated water reservoir/reservoir holder and/or feeder,and sometimes are about 90% or more nested when they do not include suchstructures. Such nesting calculations often are performed when no othercomponents are in the cage base or cover (e.g., no bedding material atthe bottom of the cage base).

A cage component sometimes comprises a nesting separation member thatfacilitates separation of nested cage components or substantiallyreduces or prevents compression of nested cage components. Compressionor over-nesting of components can lead to nested components adhering toone another and interfere with freely separating nested units from oneanother. In certain embodiments, the nesting separation member is acurved member or indent member located at or near a flange member (e.g.,see FIG. 11), for example. In some embodiments, a cage componentsometimes comprises an indent or boss that butts (e.g., interferes with)a corresponding indent or boss of an adjacent nested cage base. Edgesand/or corners of such bosses or indents sometimes are defined by aradius of 0.03 inches or less. Such an indent or boss can facilitateseparation of the nested cage components from one another, and canprevent or substantially reduce compression and sticking of the nestedunits to one another.

Thus, in certain embodiments provided are nested sets of animalcontainment cage bases comprising cage bases having a bottom and a wallor walls, where the cage bases are about 75% nested or more. The wall, asubset of the walls or all walls often taper inwards towards the bottom.The cage bases sometimes are about 80% nested or more and can be 85%nested or more or about 90% to about 95% nested. Also provided arenested sets of animal containment cage covers comprising covers that areabout 70% nested or more. The animal containment cage covers sometimesare about 80% nested or more, and can be 85% nested or more or about 90%to about 95% nested. The covers sometimes comprise one or more air inletapertures and/or air exhaust apertures, one or more air exhaustconnectors and/or one or more air supply connectors. Provided also is anested set of animal containment cage food trays comprising sidewallsand a bottom constructed from a polymer and apertures, where the foodtrays are 70% nested or more. The animal containment cage food trayssometimes are about 80% nested or more, and can be 85% nested or more orabout 90% to about 95% nested. Each component of the nested componentsoften is constructed from a polymer and often is about 0.01 inches toabout 0.08 inches thick. Examples of polymers and thicknesses aredescribed above. In some embodiments, cage bases with bedding materialare nested before or after use. Nesting cage bases with soiled beddingmaterial may substantially reduce emission of substances in the soiledbedding.

Sensing, Detection and Monitoring Devices

A detector of one or more animal emissions or cage conditions sometimesis in association with a cage. Any detector can be utilized that detectsan animal emission (e.g., ammonia) or a cage condition (e.g., humidity,temperature, airflow). In some embodiments, the detector comprises asensing probe, where the probe sometimes traverses or pierces through acover member, sometimes passes through an aperture in a cover member(the aperture sometimes is defined by a break-away member), and/orsometimes is sealingly associated with the top surface of a cover. Insome embodiments, the probe contacts the top surface of the cover at aporous zone in the cover allowing the probe to contact cage conditions(e.g., gases and fluids). In certain embodiments, a sensing probe islinked to a monitor device that detects one or more conditions oremissions, sometimes continuously.

In some embodiments, the detector comprises one or more chemicalcompounds capable of changing a property when contacted with aparticular condition or emission. For example, the detector sometimescomprises one or more chemical compounds that change color when aparticular level of ammonia accumulates in a cage. In such examples, thechemical components sometimes are contained within or on anothermaterial. Such detectors sometimes are associated with a transparent orsemi-transparent member of a cage, and the detector is associated ormated to a cage member by any convenient technique (e.g., the detectorand cage member sometimes are connected by an adhesive or a detector isplaced in a holder member mounted to the cage member). A detector oftenis mounted on the surface of a cage component, such as an inner surfaceof a base sidewall member or the bottom surface of cover member, and acolor change, for example, can be detected visually through thethickness of a transparent member of a cage. Such detectors can beutilized to detect conditions other than a minimum ammonia level, suchas temperature and/or humidity, for example.

In some embodiments, a detector that senses cage changes is utilized.Any detector suitable for detecting cage change frequency can beutilized, such as a microswitch, for example. Such a detector often iscoupled to electronics and a computer for following the number of cagechanges over a period of time, determining the frequency of cagechanges, assigning a time stamp for cage changes and determining changeintervals, for example. Other detectors also may be utilized, such asmotion detectors that sense the activity or non-activity of animals in acage, for example. Detectors sometimes are connected to or are inassociation with a rack unit, described hereafter.

In some embodiments, a detector that senses airflow and/or air pressureis utilized for monitoring and optionally adjusting supply air to cages.Known sensors can be utilized in such embodiments. Depending upon howoften cages are cleaned or exchanged, airflow volume sometimes willrequire adjustment. Over time a HEPA filter and/or pre-filter can clogwith contaminates resulting in higher impedance to airflow. The systemcan be adapted to adjust in such circumstances to maintain equal airflowuntil a threshold is met and the user must service the filters. Suchairflow, air monitoring and control devices are described in greaterdetail hereafter.

Reusable Cages

Reusable cages often include similar designs and components asdisposable cages described herein. Reusable cage components often areconstructed from a polymer suitable for injection molding, can withstandautoclaving and have good impact strength. Non-limiting examples of suchmaterials are polycarbonate and polysulfone. While the thickness of eachcage component may vary throughout, the thickness often is uniformwithin a component. The thickness of a reusable cage component sometimesis between about 0.060 inches to about 0.125 inches.

A reusable cage assembly may include one or more components forreversibly joining two or more components together. Such a componentsometimes is a gasket for joining a cage base to a cage cover. Such agasket often surrounds an outer surface of a base unit cover andsometimes surrounds an inner surface of a cage base. The gasket often isadhered to one of these cage members (e.g., base or cover) and sometimesis reversibly attachable. A gasket sometimes contains a ridge (one ormore), angled or vertical with respect to the gasket surface, whichoften surrounds the outside of the gasket, and that can deform ordeflect when the gasket, cage base and cage cover are mated. The gasketcan allow the cage cover and cage base to engage in an interference fitor snap fit. A gasket is constructed from any suitable material forcontaining animals and for forming a seal between a cage base and cover.The material from which the gasket is constructed may be elastic or maybe non-elastic, and sometimes is a material such as rubber, plastic orsilicon.

Another component reversibly joins a filter to a cage cover, and oftenis a filter cover or support that reversibly mates with a correspondingstructure in the cage cover. The component sometimes is a cover thatsandwiches the filter between it and a corresponding structure on a cagemember. The component also may be a

A reusable cage often will not contain a metal connector that connectsventilation tubing, especially not in the base, or that connects a cagecover to a base. A reusable cage may include an optional aperture (e.g.,one or two apertures) through which an air supply or air exhaust tubefrom a rack unit may be inserted.

Examples of reusable cage embodiments are illustrated in FIG. 19, FIG.20, FIG. 21, FIG. 22, FIG. 23, FIG. 24 and FIG. 25. FIG. 19 shows a topisometric view of an assembled reusable cage embodiment. Shown is ageneral overview of an assembled cage embodiment from the upper frontperspective. The reusable cage assembly is of a similar design asdisposable cage parts and assemblies shown in FIG. 1 to FIG. 18, andtherefore water bottles and food troughs are interchangeable betweensingle-use and reusable cages. FIG. 20 shows an exploded view of thecage assembly embodiment from the upper rear perspective. Shown areindividual parts that comprise the cage assembly. Food trough (305) maybe of the same geometry as for disposable food trough embodimentsdescribed herein, and the reusable version often is constructed frommetal or thick plastic. Water bottle (303) may be of the same geometryas for disposable water bottle embodiments described herein. Filterassembly (304) snaps into the dished area in lid (301) and secures thepaper below it to the lid. FIG. 21 is a cross sectional view taken atthe center of the water bottle in a reusable cage embodiment. The waterbottle is seated in the cage lid in a manner similar to or the same asin disposable embodiments described herein. Sealing mechanism (311) iseffected by elements (301) and (300) and flange (310) supports. FIG. 22is a close-up view of seal (311). Ridges (314) surround the entireperimeter of the lid (301) and contact the cage base member (300) toform a seal. Gasket (313) is a flexible material (e.g., soft rubber)that often is permanently attached to lid (301). Ridges (314) interferewith member (300) slightly so that the flexible material compresses anddeforms to provide a seal. The flexible material may be coated with ametal cloth to reduce the sliding friction experienced when removing thetop cover. FIG. 23 is a bottom isometric view showing gasket (313)surrounding the perimeter of cage lid (301).

FIG. 24 shows a filter component that can be removeably attached to acage cover. The cage cover in an embodiment includes a depressed surface(321) comprising an array of apertures (322). The flat filter component(323) is depicted in a cross sectional view and is installed at the topof the cover. The filter component comprises a flexible and elastic pane(324) (e.g., often constructed from a plastic or metal material) towhich the filter medium (e.g., filter paper) is adhered, often to theunderside of the pane. The user deforms the filter assembly into apartial cylindrical shape, often by applying squeezing pressure to theassembly, and then installs the assembly in the cover. When coupled withthe cage cover, a portion of the filter assembly is lodged under a lipor overhang in the cover. FIG. 25 shows another view of the deflectedfilter assembly installed in the cover and illustrates the filterassembly conforms to the shape of the cover. The filter frame maycontain other structures, such as arch structures, which can act assprings that apply constant and uniform pressure thereby conforming thefilter assembly into the top cover depression. The assembly results inthe filter paper tightly conforming to the top cover.

Rack Units

Rack units sometimes are referred to herein as “cage mounting platforms”or “cage mounting systems.” The racks sometimes are modular and can beassembled from reversibly connected rack modules. A rack module is ofany configuration that allows for reversible stacking in a vertical orhorizontal configuration. A rack module sometimes comprises a bottommember, two sidewall members a top member, and sometimes a back memberand front member (e.g., a skin), where the sidewall members often areparallel or substantially parallel and the top and bottom members oftenare parallel or substantially parallel. In some embodiments, rackmodules are connected by two connection members, one on each side of themodule, where the connection member is a post that inserts into anaperture in a rack module. In some embodiments a rack module comprisesfour horizontal posts vertically extended from each corner of arectangular bottom member, and connected to a rectangular top member. Arack module is constructed from any material of sufficient resilience toallow for repeated assembly and disassembly of rack units. Examples ofmaterials used to construct a rack unit module include metal alloys(e.g., sheet metal) or polymers and the like and combinations of theforegoing. A rack module often comprises airflow components, oftenlocated internally, such as plenums, cage supply tubes, and exhaustports, which are described hereafter.

A connection member for linking one rack module to another sometimes isintegrated with one of the rack unit modules and sometimes is separatefrom the module and/or other modules in the rack unit. In someembodiments, a connection member is engaged with a correspondingconnection member in a first rack module and a second rack module, wherethe first and second rack modules are connected reversibly. In certainembodiments, a first rack module comprises a first connection member anda second rack module comprises a second connection member complementaryto the first connection member, where the first and second connectionmembers may be engaged with one another to form a reversible connectionbetween the first and second rack modules. A connection member in a rackmodule can be configured in any manner that limits the movement of acage module with respect to another connected cage module and allows forconvenient disconnection and reconnection of the modules. In someembodiments, connection members are engaged and/or disengaged without atool (i.e., rack modules can be assembled and/or disassembled by hand).In certain embodiments, a connection member comprises a groove or flangeon one or more surfaces of a rack module adapted to receive, sometimesslideably receive, a corresponding flange or groove on or in anotherrack module.

In some embodiments, a connection member includes a post that insertsslideably into an aperture and corresponding component in a rack module.The corresponding component often is of a geometry substantiallyidentical to the post except that it has a larger cross-sectional areathan the cross-sectional area of the post which allows the post to slidewithin it. One or more exterior surfaces of each shelf module sometimescomprises one or more mounts and/or connectors configured to detachablyconnect and orient another rack module. In some embodiments, a rackmodule comprises one or more mounts and/or connectors configured toreceive one or more detachable shelf members, and in certainembodiments, a rack module comprises one or more shelf members. The postsometimes comprises one or more guides for alignment in a correspondingmember of a rack module (e.g., a lead-in or tab member, sometimesextending at an angle with respect to the length of the post), sometimescomprises one or more support members (e.g., a stud member) thatdecrease lateral movement when the post is inserted in a correspondingmember of a rack module, and sometimes includes one or more joggles thatfacilitate entry of the post into the corresponding member (examples ofsuch members are described in specific embodiments hereafter). A rackmodule sometimes comprises a side support that minimizes orsubstantially prevents lateral movement when modules are joined. Thepost and corresponding component sometimes have a rectangular, square,rhomboid, circular or ovoid cross section and are of sufficient lengthto support two rack units in a vertical orientation. In someembodiments, the corresponding component comprises one or moreprojections that limit the distance the post slides through it. The postand/or corresponding member in the rack module often include holesthrough which connectors may be inserted to fix the position of the postwithin the corresponding member. Any connectors may be utilized, such asscrews, pins and/or bolts, and sometimes a connector is depressible andintegrated with the post.

A rack module sometimes is connected to another component other thananother rack module. In some embodiments, a rack module is mounted ontoa tram member, sometimes via a connector, where the tram is configuredfor transportation of a rack module or plurality of rack modules (i.e.,a rack unit). A rack module sometimes comprises one or more mounts onone or more exterior surfaces which can be utilized to reversibly attachanother component of an animal containment system, such as one, two ormore airflow assemblies, for example (described hereafter).

One or more cages can be stored on or in a rack module, and anyconvenient configuration for storing a cage can be utilized. A cagesometimes is placed on a surface of a rack module and stored for aperiod of time. A cage often resides on a shelf connected to the rack. Arack module sometimes comprises one or more mount members useful forstoring one or more cages in or on the rack module. A correspondingmount member sometimes is located on one or more outer surfaces of acage and is adapted to connect with a mount member located on a rackmodule. In certain embodiments, a mount member is a groove or flange onone or more surfaces of a rack module and is adapted to receive,sometimes slideably receive, a corresponding flange or groove on or in acage. There is sufficient distance between the top of a mounted cage andthe lower surface of a rack module located above the cage to permitairflow out of the cage in such embodiments.

A rack module may comprise one or more carriages suitable for contactinga cage with another component. In an embodiment, a carriage sometimesassociates a component with one cage or multiple cages. A carriage canbe utilized to contact a cage with any component, such as an air supplyconnector, an air exhaust connector, a central water supply connectorand a detector or sensor, for example. A carriage often is connected toa shelf in such embodiments. Any suitable carriage can be utilized, suchas a carriage comprising a piston or lever, for example, and can beconstructed from any suitable material, such as a metal alloy and/or apolymer, for example. The carriage engages a component with a cagemember (e.g., a cage base or cage cover) in any suitable manner,sometimes by a linear, arc, vertical or horizontal motion, orcombination thereof. The carriage often includes a holder that retains acomponent that is engaged with a cage member. The carriage sometimes isoperated by hand and sometimes is operated remotely by mechanicaloperation and/or computer-controlled operation, for example. In someembodiments, a carriage is useful in part for orienting the position ofa cage in a rack unit, as the carriage often can only engage the memberit holds with a cage when the cage is properly oriented on a rack unit.In some embodiments, a carriage applies mechanical pressure to the cageand thereby holds it in alignment. In certain embodiments, a carriagecomprises a mechanism that holds its position away from the cage, whichcan be disengaged for engaging a component of the carriage with a cagecomponent.

In some embodiments, the carriage comprises a lever connected near to anend or at one end of a rack or shelf unit via a hinge and a holderadapted to receive one or more components reversibly associated with acage. Such a lever often includes a spring that applies downwardpressure to the lever when a component to which it is connected isassociated with the cage. In certain embodiments, a rack unit comprisesone or more carriages connected to an air supply or air exhaustconnector (e.g., one, two or more air connectors or nozzles) andreversibly contact the connector(s) with a cage. In some embodiments,the air supply connector and optional air exhaust connector is conicaland the cage cover member comprises a conical void adapted to sealinglyand reversibly connect with each conical connector. In some embodiments,a carriage comprises one or more projections (e.g., pins) that can beslideably positioned through one or more corresponding structures of thecage adapted to receive the projection(s) (e.g., one or more aperturesin a flange member), which are useful for orienting a cage in a rackunit.

Air supply and exhaust conduits sometimes are located within walls of arack module, and no exterior plumbing is required in some embodiments.An air conduit system sometimes comprises a conduit of comparativelylarge volume connected to the blower, sometimes arranged in a verticalorientation in a rack module, which is connected to one or morecomparatively smaller volume conduits that supply/exhaust air for agroup of cages in a manifold of conduits often arranged horizontally. Avertical air conduit sometimes is referred to as a “tube” herein. Airtubes and conduits are of any shape and are constructed from anymaterial suitable for providing air to or exhausting air from animals.In some embodiments, the manifold is constructed from rigid tubingconnected to flexible tubing that supplies or exhausts air from eachcage. Such flexible tubing sometimes is connected at one end to a clampor metering nozzle in association with a manifold conduit and at theother end to a nozzle that can be engaged with a cage. An air meteringnozzle often is located between air supply conduit and an air supplynozzle that engages the cage. Each end of a flexible tube may bereversibly coupled to a nozzle or a clamp, sometimes by a twist lock orquick release coupling, and sometimes is integrated with the end ofthese components. A nozzle (i.e., outlet member) is constructed from anymaterial and is of any shape convenient for delivering air to an animal.In some embodiments, the outlet member is a hollow cylinder structure,having tapered or un-tapered walls, or an acicular or needle structure.

A nozzle is engaged with a cage in any convenient manner thatprovides/exhausts air to contained animals. In some embodiments, thenozzle is a connector that mates with a corresponding structure in thecage assembly, often forming an air-tight, reversible seal. The nozzleis of any geometry suitable for delivering/exhausting air to/from ananimal cage assembly, and sometimes is conical. In conical connectorembodiments, the smaller horizontal surface area sometimes is locatedbelow the larger horizontal surface area when the nozzle is oriented forair passing vertically through it, and the conical connector oftenincludes a void, sometimes a cylindrical or conical void, defined byapertures in the top and bottom surface of the connector. In someembodiments, one or two nozzles passes through a cage cover member,sometimes through a portion of the cover thickness or trough the entirecover thickness. A nozzle may extend through the exterior and interiorsurfaces of a cover member, sometimes pierces through a cover memberhaving no aperture or other structure for receiving the nozzle, andsometimes extends through an aperture formed by a break-away portion ofthe cover member. Where a nozzle pierces through a cover member, it canpierce through a flexible region in the cover member, and material inthe cover may form an air-tight or semi air-tight seal with the outersurface of the nozzle. A nozzle and other members of the airflow systemoften are not connected to a sidewall member of a cage (e.g., notconnected to a sidewall member of a cage base). Air often enters a cagethrough a cover member, often via a nozzle from an airflow system, andoften exhausts through an exhaust nozzle to an airflow system and/orexhaust aperture(s) juxtaposed with a filter in the cover member. Airoften does not exhaust through a cage base.

The conduit system in a rack sometimes includes no adjustable valves. Ametering nozzle, often having a fixed aperture, can regulate airflow andair pressure in certain rack embodiments. A conduit system may compriseone or more valves in certain embodiments. Any valve useful forconstricting airflow can be utilized. One or more valves sometimes arelocated at a junction between a main supply/exhaust conduit, manifoldand/or flexible tube, sometimes are located at the end of a flexibletube connected that is connected to a cage, and sometimes are locatedwithin the length of a main supply/exhaust or manifold (e.g., at aregion not at a terminus of the conduit). In certain embodiments, theinterior cross-sectional surface area of a conduit (e.g., thecross-sectional circular surface area of a tube) is smaller, and in someembodiments, is substantially smaller, than the interior cross-sectionalsurface area of the a larger conduit to which it is connected. Such aconfiguration is useful for providing substantially equal airflow andair pressure to each cage without control valves in the system toregulate airflow and pressure to each cage. For example, the interiordiameter of a connector between a manifold conduit and a flexibleconduit linked to a cage (e.g., a clamp system described herein)sometimes is about 0.05 inches and the interior diameter of the manifoldconduit sometimes is about 0.25 inches or larger. The limiting apertureoften is in a metering nozzle and sometimes is in a clamp assembly thatcouples cage-connected conduit to a manifold conduit (e.g., the interiorcross sectional diameter of air fitting (72) in FIG. 23A).

In specific rack unit embodiments a rack unit module comprises front,back and two side panels and contains within the panels an air supplymanifold and tubing connecting the cage bases to the air supplymanifold. Such rack units sometimes comprise an air exhaust manifold andtubing connecting the cage bases to the air exhaust manifold. Theremaining space within the panels sometimes is referred to herein as a“plenum.” Air can be scavenged directly from cages through tubingconnecting each cage to an exhaust manifold, when present, within thepanels. Air also can be scavenged from cages by applying negative airpressure within the plenum (e.g., by connecting a tube from an HVACsystem to the plenum) and air leaving a cage via its filter is exhaustedinto the plenum through adjacent ports in the panel in contact with eachcage. The latter method can be utilized in addition to or instead ofexhausting air through exhaust manifolds. Where the rack unit includesan air supply and air exhaust manifold, and each manifold is engagedwith each cage via connection tubing and air separate supply and exhaustnozzles, positive air pressure and negative air pressure can becontrolled to provide only positive air pressure, only negative airpressure, or a combination thereof. A cage may comprise an air filtermedium or non-porous medium juxtaposed with apertures in the cover oranother member (e.g., aperture array) in such embodiments.

In some embodiments, a rack unit module is connected to another rackunit module by a flexible tube connected to an air supply conduit and/orair exhaust conduit and one or more separate inserts that slideablyengage a corresponding receptacle(s) in the other rack module. In thelatter embodiments, a rack module may comprise one or more guides forconnecting the modules to one another. In such embodiments, air supplyand/or air exhaust plumbing is coupled/decoupled at the same time rackunits are engaged to/disengaged from one another.

Certain related embodiments are directed to a clamp for connecting oneair conduit to another air conduit having at least one hole along itslength. The clamp comprises a body containing three voids and a slot,where the first void has a circular cross section extending with theslot from the top of the body to the bottom of the body; the slot isextensive with the length of the circular void; the second void extendsvertically from a point along the length of the first void to a side ofthe body; the third void extends perpendicular to the first void fromthe opposite side of the body the second void emerges and through theslot; and the circumference of the circular void is greater than theouter circumference of the conduit containing the hole. All of the voidsoften have a circular cross section, although other cross section shapesmay be utilized. The clamp sometimes is provided with a screw that canbe threadably engaged with the third void. Application of the screw inthe third void can reduce the circumference of the first void so thatthe clamp tightens around the conduit to form an air tight seal.

Thus, some embodiments are directed to modular rack components. Providedin certain embodiments is an animal containment rack comprising two ormore rack modules, where each rack module comprises shelves, a tube, anair supply or exhaust connector at one end of the tube (e.g., blowerconnection) and conduits connected to the tube that deliver air from ablower at each of the shelves. Also provided are animal containmentracks comprising two or more rack modules, where each rack modulecomprises air metering nozzles, a tube, an air supply or exhaustconnection at one end of the tube (e.g., air blower connection) andconduits connected to the tube that deliver air from a blower to each ofthe metering nozzles. The rack modules sometimes are joined by a sleeve(e.g., flexible tube) that receives a tube from one rack module and atube from another rack module, and sometimes a rack module is connectedor disconnected to another rack module without a tool. Each rack moduleoften comprises a guide that orients the rack module with acorresponding guide of another rack module during assembly of the animalcontainment rack. A modular rack can comprises a tram.

In certain embodiments, provided are animal containment racks comprisinga tube, an air supply or exhaust connection at one end of the tube(e.g., air blower connection) and conduits connected to the tube thatdeliver air from the blower to metering nozzles, where air pressure(e.g., measured at the metering nozzles) is about 0.3 inches of water orgreater. Such racks sometimes are modular, and in some embodiments arenot modular. Air pressure (e.g., measured at the metering nozzles)sometimes is about 0.4 inches of water or greater, about 0.5 inches ofwater or greater, about 0.6 inches of water or greater, about 0.7 inchesof water or greater, about 0.8 inches of water or greater, about 0.9inches of water or greater or about 1.0 inches of water or greater. Insome embodiments, the air pressure is about 1 inches of water to about 3inches of water, and can be about 2 inches of water. The pressure of airsupplied at each metering nozzle often is not regulated by an adjustablevalve and often is regulated by the metering nozzle. The orificediameter of the metering nozzle often is about 0.25 inches or less, andsometimes is about 0.06 inches to about 0.08 inches.

In certain embodiments, a rack comprises an airflow or air pressuresensor. The sensor sometimes is in connection with one or more of atube, a conduit and/or a metering nozzle. A rack in some embodimentscomprises one or more shelves each in proximity to a metering nozzle.

Also provided in some embodiments are animal containment rackscomprising shelves, a tube, an air supply or exhaust connection at oneend of the tube (e.g., air blower connection) and conduits connected tothe tube that deliver air from a blower at each of the shelves, whereeach of the shelves comprises a carriage and an air supply connectorjoined to the carriage that can mate with a corresponding connector ofan animal containment cage; and the air supply connector is effectivelyjoined to one of the conduits (e.g., by flexible tubing). In someembodiments, an air exhaust connector is joined to the carriage that canmate with a corresponding connector on an animal containment cage. Thecarriage, when operated, can mate the connector with a correspondingconnector of an animal containment cage or can un-mate the connectorwith the corresponding connector of the animal containment cage. Thecarriage is a lever in some embodiments, and the air supply/exhaustconnector of the carriage is of any geometry that can mate with acorresponding connector of the cage (e.g., conical projection or conicalvoid).

A rack sometimes further comprises one or more animal containment cageson the shelves, and one or more of the animal containment cages maycomprise one or more animals. A rack can comprise an air blowerconnected to a vertical tube of a rack in certain embodiments, and theair blower sometimes comprises two or more fans oriented in series. Insome embodiments, the air blower is an air supply blower, and in someembodiments, an air exhaust blower is joined to a rack.

In some embodiments, provided are animal containment racks comprisingshelves, a tube, an air supply blower connected at one end of the tube,conduits connected to the tube that deliver air from the blower at eachof the shelves and an airflow or air pressure sensor, where a controlleradjusts air delivered by the air supply blower based upon a set pointand a signal from the sensor. In such embodiments, the sensor sometimesis in connection with a tube, a conduit, an air metering nozzle, a cageor combination of the foregoing. The air supply blower sometimescomprises two or more fans oriented in series and the controller adjuststhe speed of one or more of the fans. The rack sometimes comprises anair exhaust blower, and the air exhaust blower can comprise two or morefans oriented in series and the controller adjusts the speed of one ormore of the fans. The controller sometimes is linked by wire to theblower(s) and sometimes it is remote.

Specific rack unit embodiments are shown in FIGS. 26, 27, 28, 29A, 29B,30, 31, 32, 33, 34A, 34B, 35A and 35B. FIG. 32 is a bottom isometricview of a rack module. Support (80) is the shelf assembly that hooksonto wall (70), which includes conical air supply and air exhaustconnectors attached to a carriage that pivots up and down. Section (71)is a cut-away view of the internal plumbing (e.g., FIG. 33 provides aview of the plumbing in greater detail). (80) shows the conical airinsert member. (81) is a block with an airflow passage the directs theairflow in a 90 degree bend.

FIG. 26 is a cut-away bottom isometric view of a rack module and FIG. 27is an expanded view of region (71). Exhaust tube manifold (74) pulls airfrom each cage. Supply tube manifold (75) delivers air into each cage,which rests on a shelf assembly (80). Manifold (74) and manifold (75) isconstructed of any material suitable for delivering air to animals, suchas stainless steel tubing, and other metals or plastic could be used.Clamp (73) is constructed from a suitable material (e.g., a plastic suchas nylon) for clamping onto manifold (74) or manifold (75) to divertairflow to or from each cage. Clamp (73) also serves a mechanicalfastener for the manifold tubes. A skin (79) conceals the internaltubing and creates a plenum for the other exhaust air. Internal rib (90)supports the shelves. Air fitting (72) threads into clamp (73). Airpasses through this fitting on the way to or from each cage via flexibletubing.

FIG. 28 is an isometric view of the clamp assembly. Self-tapping screw(76) is used to tighten the clamp (73) onto manifold (74). Air fitting(72), also referred to herein as a “metering nozzle,” is of anyconvenient geometry for receiving tubing, such as flexible tubing, thatis connected to an air supply or air exhaust connector to deliver orexhaust air, respectively, to or from a cage.

FIG. 29A is a cross-sectional view and FIG. 29B is a top view of theclamp assembly. A hole is drilled or punched in manifold (74) thatallows air (78) to flow in or out of clamp (73). Skin or rib (77)secures the tube manifold clamp assembly. Air gap (79) allows the clampto stretch and shrink over the manifold (74).

FIG. 30 is a top isometric cut-away view of the upper right portion of arack module. A flexible hose (e.g., rubber hose) connects air fitting(501) to tube (506) but is not shown. Flexible hose connector (502)couples multiple rack modules together. Manifold (74) and manifold (75)are shown.

FIG. 31 is a cross sectional view of connector (502) in FIG. 30.Vertical tube (510) often is a rigid tube such as a stainless steeltube. Annular barb (501) ensures a flexible connection hose does notslip or leak. Air passage (504) flows air from the vertical direction tothe horizontal direction. Four passages (504) sometimes are incorporatedin each module to flow air to four rows of cages. Mounting boss (507)can be utilized to attach the connector to the side of the module, andno air flows in this region.

FIG. 32 is a front view showing two rack modules positioned forconnection. Vertical tube (510) is a rigid tube running vertically fromthe bottom to top of each module. Tube (518), which often is flexible(but may be substantially inflexible in certain embodiments), can slideover the taper at the bottom of tube (510) for coupling. A raisedannular rib (511) ensures a tight fit between rigid tube (510) and tube(518) to avoid air leakage. The modules are mated when mating surfaces(514) and (515) are contacted and surfaces (517) and (516) arecontacted. Alignment tab (513) facilitates mating of the modules even ifconnection members are not initially in perfect alignment. Pin (512)directs alignment, as shown in FIG. 33. The coupling mechanism showneliminates the requirement for external hoses and clamps and reducestime required for any disassembly and assembly for cleaning. FIG. 33 isa right side exploded view of a rack module. Pin (512) guides eachmodule onto the same centerline. Slot (519) is adapted to slideablyreceive the pin (112). Annular rib (511) can force tube (518) tostretch, thereby providing for an interference fit seal.

FIG. 34A is a bottom isometric view of a shelf assembly (80) embodiment.The shelf supports each cage and also supplies airflow to the cagebelow. Nozzle (220) near handle (221) of shelf (222) supplies air intothe cage when lever (224) is in the down position. Lever (224) alsoactuates lever (249) to engage or disengage rear nozzle (220). The rearnozzle often is utilized to exhaust air from a cage. The separation ofthe nozzles provides front to rear airflow or rear to front airflow.Nozzles (220) are directly connected with conical receptacles (145) and(146) in a cage lid, and the tapered cone shapes facilitate asubstantially air-tight seal. Springs attached to both levers provide asoft down force on nozzles (220) to prevent leaks when coupled to thecages. Ergonomic handle (221) is engaged by a user to actuate the levermechanism. Edge (225) shows an embodiment in which sheet metal whenhemmed or folded over onto itself can reduce edge sharpness. FIG. 34B isa front view of the shelf assembly embodiment. Plastic bezel (223)reduces edge and corner sharpness on the front of the shelf. A reductionin edge sharpness is advantageous when a user is wiping shelves with atowel for example. Vertical slot (226) guides lever (224) in upward anddownward directions. Plastic bushing (223) provides free movement of themetal lever.

FIG. 35A is a side view of the shelf assembly (80) embodiment andillustrates lever containment. Lever (224) pivots about pin (243) inslot (242). Lever (224) can be locked into the up position when (241)rests in the depression of slot (240). When pin (240) is positionedupward, pin (245) is positioned downward. This motion causes lever (249)to rotate about pin (246). FIG. 35B shows the shelf assembly embodimentin FIG. 35A with handle (221) in the up position. The resulting leverposition raises nozzle (220) out of a cage so a user may remove thecage. Hook (248) on the shelf assembly supports the shelf on the rackmodule.

Airflow Units

An animal containment cage and/or rack is ventilated in certainembodiments. The cage and/or rack sometimes is ventilated by a positivepressure only, a negative pressure only or a combination of a positivepressure and negative pressure. In certain embodiments, the pressure is0.3 inches of water or greater, and the pressure can be about 0.4 inchesof water or greater, about 0.5 inches of water or greater, about 0.6inches of water or greater, about 0.7 inches of water or greater, about0.8 inches of water or greater, about 0.9 inches of water or greater orabout 1.0 inches of water or greater. In some embodiments, the pressureis up to 5 inches of water. Thus, an animal containment system sometimesoperates in a positive pressure mode, meaning the pressure in the cageis higher than the outside environment. An advantage of this mode is noor negligible outside contamination can leak into the cage and harm ananimal resident. If a disease breakout occurs, a negative pressure modemay be desirable and can be employed. Pressure in each cage is lowerthan the outside environment pressure in a negative pressure mode.Negative cage pressure reduces the possibility a disease spreads outsidethe cage. A containment system often includes one supply blower thatgenerates positive pressure and sometimes includes one exhaust blowerthat generates negative pressure. The speed of each blower is adjustableto allow for a selection of full positive pressure, full negativepressure, or any differential pressure between.

An airflow unit generally comprises a blower and sometimes comprises aconduit, a filter, a heater, air cooler, humidifier, de-humidifier,deodorizer and/or one or more control devices. Any blower suitable forproviding air to animals is utilized. A conduit system delivers air froma blower member to one or more cages in an animal containment system.

An airflow unit sometimes comprises an airflow sensing system andsometimes comprises a control system. An airflow sensing systemcomprises one or more sensing members that detect one or more parametersthat vary in an animal containment system (often referred to as“containment parameters”) and a reporting member that generates a signalfor the parameters. Examples of containment parameters include but arenot limited to temperature, air pressure and/or humidity, and any probefor monitoring such parameters can be utilized. A sensing member islocated in any convenient location for sensing a containment parameter,such as an airflow detector located in a main supply/exhaust conduit. Insome embodiments, the sensing member is in contact with a cover memberof a cage, sometimes at the surface of a cover member and sometimesextending through the cover member into the interior of the cage. Inairflow units comprising a control system, the system comprises one ormore control members that modulate the output of one or more members ofthe airflow system (e.g., blower, humidifier, de-humidifier, heater, aircooler). The control member sometimes is operated manually, andsometimes, a control member is in communication with a sensing memberand automatically modulates the output of a member of the airflowsystem. Suitable control methodology can be utilized, such as PID or PICcontrollers and use of blower speed control circuits, and examples ofairflow control systems are described in U.S. Pat. Nos. 6,357,393 and6,408,794. In an embodiment, the control member registers a signal fromthe sensing member, and if a deviance from a set value for the parameteris detected, the controller communicates a signal to another member ofthe airflow unit to increase or decrease its output. For example, wherethe sensing member is an air pressure sensor, and an air pressuregreater than a value set for the controller is sensed, the controllersends a signal to the blower to decrease its output.

Airflow units sometimes are connected to exhaust ports located in a rackunit module. Slots strategically placed near the rear of each cage canscavenge air exhausted from the cages when present. Exhausted airsometimes contacts a filter in the airflow system, such as a carbonfilter (e.g., charcoal filter) in an exhaust manifold or in a separatefilter unit through which exhaust air passes.

An airflow unit sometimes is configured to reversibly attach to a rackunit. The airflow unit can attach in any orientation to the rack unit,and in some embodiments, it is reversibly mounted to a top surface of arack unit. An airflow unit sometimes comprises a connector member thatmates with a connector member on an exterior surface of a rack unit. Anyconnector member(s) allowing for convenient assembly and disassembly ofan airflow unit and a rack module can be utilized, including but notlimited to connectors described herein for rack modules. An air supplyblower or air exhaust blower sometimes is connected to a tube (e.g.,vertical tube), and an air exhaust blower sometimes is connected to aplenum.

In certain embodiments, a blower assembly is in connection with a rackmodule adapted to receive cages for housing animals, where the blowerincludes two fans in series. Orienting fans in series offers advantagesof decreased noise levels and decreased vibration compared to non-seriesunits that deliver the same or similar air pressure. Such blowerassemblies may be used for providing positive pressure for air supplyapplications or negative pressure for air exhaust applications. In someembodiments, a blower assembly utilized for providing negative pressureincludes a chamber that includes an aperture, sometimes an adjustableaperture. In the latter embodiments, the blower assembly can beconnected to an HVAC system, the latter of which oven provides variablenegative pressure, and render the negative pressure applied to theanimal containment system constant. A constant pressure may be achievedas excess negative pressure exerted by an HVAC system causes air outsideof the animal containment system to flow into the chamber, oftenreferred to as a mixing chamber, rather than pulling air from the animalcontainment system.

In certain embodiments, animal containment system blowers comprise twoor more fans in series, where the blower delivers an air pressure ofthree inches of water or more. The blower sometimes comprises three ofmore fans in series, and can comprise a fan speed controller inconnection with each fan, where the fan speed controller can be linkedto one or more air pressure or airflow sensors.

Specific airflow unit and animal containment cage airflow embodimentsare shown in FIGS. 36, 37, 38 and 39. FIG. 36 is an isometric view of ansupply air blower enclosure. Blowers (730) are mounted in the assemblyin series. In this arrangement, air leaving exhaust port (736) of oneblower is the intake air for the second blower. An advantage of thisin-series configuration is the system pressure is additive for eachblower.

FIG. 37 is a top view of a supply blower embodiment and shows airflowpath. Air (733) enters through the side of the blower assembly. The airflows past a 90 degree bend due to the shape of the blower housing, andbrackets (732) direct airflow into the intake of the next blower inseries. Air then flows past another 90 degree bend through the secondblower and is directed into filter assembly (731).

FIG. 38 is a bottom isometric view of an exhaust blower embodiment. Thesupply and exhaust blowers are identical except the blowers are mountedon the flip side of bracket (732) for the exhaust blower. Air flowsthrough a connector (738) which couples onto a rack module in the samefashion the module connects to another module. Mixing box (740) isattached to the exhaust of the blower assembly. This is an optionalassembly that allows the user to couple the exhaust air to a HVACsystem. Rather than connecting the HVAC directly to the blower enclosureit is connected to the mixing box. Slots (741), which can be of anygeometry suitable for airflow, allow excess airflow caused by the HVACsystem to flow through the mixing box rather than alter the flowgenerated by the exhaust blower. The flow in an HVAC system generally isvariable and generally is far higher than flow provided by an exhaustblower provided herein. Mixing box (740) renders HVAC airflow constantor substantially constant as excess negative pressure provided by theHVAC pulls air through slots (741) instead of through the exhaust blowerunit. The flow generated by the exhaust blower mixes in the box andenters the HVAC system. This method prevents odors from entering theroom, and offers control of the rack airflow. Mixing box (740) mayinclude a sliding cover that can be positioned to partially cover slots(741) so that the mixing box may be adapted to different HVAC systems.Airflow streamers also may be positioned near slots (741) to indicatedin which direction air is flowing (e.g., as the intended flow directionis inward, streamers can be utilized for any troubleshooting). The flowin both blowers in some embodiments is under constant control via amicroprocessor that regulates flow.

FIG. 39 is a side view of a module assembly. Exhaust flow (550) can beattached to an HVAC system and/or an exhaust blower. In embodimentswhere a rack system is utilized in positive pressure mode some airflowcan exit cages via an exhaust array covered by a filter. A large portionof this flow can be scavenged by the rack module plenum. Slots (550) inFIG. 26 exhaust air from cage exhaust arrays into the plenum. A fittingon the top of the rack couples this flow to an HVAC system. Thisconnection is optional and not required when operating at neutral ornegative pressures.

An airflow system sometimes comprises a controller or is linked to acontroller. For example, in certain embodiments blower assemblies cancomprise two or more fans, a fan motor driving each fan, a fan speedcontroller in connection with each fan motor, and one or more externalair pressure sensors in connection with the fan speed controller. Theassembly often comprises a user interface featuring readouts of certainfeatures of the blower (e.g., speed of each fan (rpm)) and user controlof blower components (e.g., speed of each fan). Air pressure sensors arelocated in any convenient portion of an animal containment system formeasuring air pressure, such as in an air supply conduit, air exhaustconduit or cage, for example. One or more signals corresponding to airpressure are forwarded to the fan speed controller in a period of time(e.g., one signal per 100 milliseconds) and the controller increases ordecreases the speed of one or more fan motors and thereby adjusts theair pressure to a set level. The fan speed controller may reduce orincrease the speed of one or more fans, or all fans, and may cut offpower to one or more fans for a period of time to adjust air pressuregenerated by the assembly. The blower assembly often includes one ormore fan speed sensors that communicate one or more fan speed signals tothe fan speed controller in a period of time (e.g., one signal per 100milliseconds). A controller also may be utilized to control airflow fromtwo or more blower assemblies, and thereby control such airflowparameters such as airflow rate, differential pressure and air exchangerate. In the latter embodiments, the controller may control (a) airoutput from one or more air supply blower assemblies and (b) air exhaustone or more air exhaust blower assemblies. The use may use thecontroller to utilize an air supply blower or air exhaust blowerexclusively, or balance the output of an air supply blower and airexhaust blower. The controller may be connected to the blowers via oneor more cables or one or more wireless transceivers, for example.

Controller circuitry and software can be contained within a controlunit. FIG. 40 is an isometric view of the controller assemblyembodiment. Plastic housing (600) is shown clipped onto a metal bracket(603) that can be attached to a convenient location on a rack module.Optional cable (607) allows electrical signals to pass between thecontroller and the blower enclosures. Cable (607) generally is notincluded when the controller assembly communicates via wirelesstransceivers. The controller can be utilized by the user to select thedesired ACH or airflow via buttons (602). The user can also select thedesired differential pressure via buttons (601). The controller displaysthe setpoint and actual values in real time on a LCD display (605). Thecontroller communicates to both supply and exhaust blowers to sensetheir speed and pressures to equal the desired setpoint. The controlleralso can identify failures such as leaks and/or blower failures. Button(604) is a mute button to silence an audible alarm. The controller canbe programmed to sound an alarm when a parameter, such as airflow or airpressure, deviates at a specified increment from the set point. Button(605) is a reset button to reset the circuitry and clear any alarms.FIG. 41 is a front view of the same controller. Approximate dimensionsin certain embodiments are 9″ width×4.5″ height×1″ depth. FIG. 42A andFIG. 43B show wiring diagram embodiments of a controller moduleembodiment.

Following are examples of controller components and parameters for usewith an animal containment system.

1. Software

a. PIC Setup: PIC peripherals include an AD converter, timer1(internal), and timer0 (internal). The A/D is setup for dual voltagereferences and a conversion clock appropriate for 20 MHz. Otherwise, allthe I/O ports are set as I/O ports.

b. Control Algorithm: The control algorithm samples the pressure signalsapproximately every 100 ms. This value is compared to the currentsetpoint (calc_setpoints), and if it is lower or higher the blower speedis increased or decreased to move the actual pressure to the desiredpressure. If the control algorithm operated at the full speed of the PICCPU, the duty cycle would swing wildly from 100% to 0%. To prevent thisfrom happening, intentional delays are introduced in the controlalgorithm to slow its response rate. The length of these delays variesdepending on how far away the current pressure is from the desiredpressure, and where the desired pressure is in an absolute sense (highend or low end). The three stages are: (a) very far away from thesetpoint: change the duty cycle rapidly; (b) near the setpoint: changethe duty cycle slowly; (c) at the setpoint: change the duty cyclerapidly, but limit the change to +/−0.02%. The distance thresholds aredifferent depending on if the setpoint is a high pressure or a lowpressure, to account for the non-linear duty-cycle to pressurerelationship. All thresholds are in counts (not including the zerooffset) and located as defines in the beginning of the code. Anytime thesetpoint is changed, fan_onoff( ) and startup_fans( ) are both executed.

c. LCD Control: The LCD is initialized at startup in a standard fashion,as indicated in the datasheet. The 4 bit interface is used, without thecursor or blinking character, to prevent shadows during updates. Afterstartup, there is really only one lcd function, which is put_lcd_byte,and its copy for interrupt use put_lcd_byte_INT. All lcd string, int,and char printing functions use this function to talk to the lcd.

d. User Interface: Any keypress generates an interrupt which tells thepic to vector to the ISR. The keypress ISR determines which key waspressed, then updates the ACH and DP (whichever is appropriate), andthen immediately updates the LCD with the new ACH and DP. If the buzzersnooze key was pressed, the snooze is reset (if the buzzer is active),and the LCD is NOT updated.

e. RPM Verification: Each blower is sequentially checked for a valid RPMsignal, every 100 ms. Ignored and bad blowers are not checked for avalid RPM signal. If a blower is checked for an RPM signal and it has aninvalid or no RPM signal, it is immediately shut off, and fan_onoff( )and startup_fans( ) is executed to start up an alternate blower ifappropriate (and available).

f. Auto Zero: At startup, all blowers are shutdown, and a 15 secondtimer is started. At the end of 15 seconds, the firmware assumes thepressure inside each manifold has reached ambient. Any voltage from thepressure sensors can be interpreted as a zero-offset. The PIC reads thisoffset, stores it, and applies it to all future pressure sensorreadings. This offset is erased at every reset.

g. Function Descriptions:

Function Description void ad_sample performs a single ADC conversionusing the current ADC (void) channel void put_lcd_byte writes a byte tothe LCD using the current register (unsigned char lcd_byte) voidput_lcd_byte_INT identical to put_lcd_byte( ), but a copy is requiredfor use (unsigned char lcd_byte) in the interrupt service routine voidupdates just the ACH and DP setpoints on the displayupdate_display_INT(void) void lcd_init(void) initializes the LCD, runsonly once at startup void lcd_print_string prints a zero terminatedstring (const char*) void lcd_print_char prints a single byte (unsignedchar) void lcd_print_int prints an unsigned integer. 4 digits, allleading zeros (unsigned int) converted to spaces void lcd_address movesthe lcd cursor to the specified locations. Top line (unsigned char) is 0through 15, bottom is 16 through 31 void calc_setpoints calculates thecurrent setpoints in counts using the (void) selected ACH and DP voidkeypress (void) in/decrements ACH and DP depending on the key pressed,or performs buzzer snooze function void calc_actual (void) calculatesthe actual ACH and DP void check_rpm checks the currently selected fan(rpm_ch) rpm for (unsigned char rpm_ch) validity and updates fan failureflag if bad void update_display completely updates the LCD displayincluding actual/set (void) ACH and DP, and alarm indicators voidstartup_fans resets the PWM to a default value and waits for all non-(void) ignored/non-bad fans to start void fan_onoff determines whichfans should be on and which should be (void) off based on which fans arebad, ignored, +/− 100% modes, and positive only mode void auto_zero runsat startup only. Determines pressure sensor offset (void) by shuttingoff all fans, waiting, and storing the value

2. MCU Board

The MCU board can have the following functions: (i) interface to the LCDand provide contrast control and backlight power; (ii) interface to bothPWM controller boards; (ii) filter the output of both pressure sensorsand provide voltage reference; and (iv) keypad input and interrupt. TheLCD can be interfaced and contrast control and backlight power isprovided. The LCD data lines connect directly to the PIC I/O port lines.The LCD contrast is controlled via R10. The lcd backlight voltage isdropped from 12V to nominal via R4. Both PWM controller boards can beinterfaced, and all control lines from both controller boards connectdirectly to the PIC CPU I/O ports. Output of both pressure sensors canbe filtered and voltage references can be provided. A 5V shunt typevoltage reference (D6) provides two stable references to the PIC ADCconverter, and powers both pressure sensors. Ports R8 and R9 allowadjustment of the voltage references, nominally set to 2.5V and 0.45V,respectively. Keypad input and interrupt can be provided, and the outputof 5 switches (keys) is debounced and connected individually to the PICI/O ports. The output of all 5 keys is OR'd together via diodes andalong with Q1 generates a keyboard-interrupt.

3. PWM Controller Board

The controller board often has the following functions: (i) increase ordecrease blower speed in response to requests from the PIC CPU; (ii)allow one or both blowers to be disconnected from power; (iii) conditionthe tachometer output of each blower for transmission to the PIC CPU;and (iv) provide a physical and electrical mounting point for a pressuresensor.

a. Variable PWM Blower Controller the controller board is designed tocontrol two blowers simultaneously. A large resistor is connected inseries with one of the blowers to create an approximately 100 rpm speeddifference at all times between the two blowers to prevent audible beatfrequencies. The voltage across the blowers (and thus their speed) isvaried using a filtered-PWM technique. A variable duty-cycle square wavewith 12 bit resolution is generated as follows: (i) U5 and U8 are usedas a 12 bit equity comparator; (ii) U3, U7, and U11 form a 12 bitup/down counter whose output is clocked up or down by the PIC CPU (PWMincrease/decrease); (iii) the comparator constantly compares acontinuously running 12 bit counter (U4) with the U3/U7/U11 counter;(iv) when the two counters are equal, the output pulse goes to aflip-flop (U6), which outputs the variable duty-cycle square wave; (v)the duty cycle varies because the output of the U3/U7/U11 counter iscontrolled by the PIC CPU, and therefore the point when the two countersis equal (and the flip flop toggles) is controlled by the PIC CPU; (vi)the PWM output of the flip flop is fed to the main switching mosfet (Q4)which the blowers are connected in series with. A large capacitor (C2)in parallel with the blowers filters the PWM output to reduce audiblehum at the PWM frequency, and to prevent the blower tachometer signalfrom becoming corrupted with PWM variations; (vii) OSC1 determines thefundamental frequency of the PWM signal. At 1 MHz, it is 1/(4096*1uS)=244 Hz; (viii) Q2, D1, and their associated passives are used toprevent the U3/U7/U11 counter from rolling over at 0 and 4096; and (ix)the 12 bit resolution of the PWM circuit allows the PIC CPU to changethe duty cycle in 0.02% increments.

b. Blower Power Control: Each blower can be independently disconnectedfrom the power supply. This function is required to allow the PIC CPU todisconnect a non-functioning blower, to use only one blower for very lowpressure settings, or to shut off both blowers if a +100% or −100%differential pressure setting is selected by the user. Q1, Q3, Q5, Q6and their associated resistors form a normally-open, active-high switchwhich can be controlled via logic levels from the PIC CPU.

c. Tachometer Signal Conditioning: Since both blowers are essentiallyfloating with respect to ground, their tachometer output measuredrelative to ground will be corrupted with very large voltage transientsresulting from the difference in voltage between the negative side of C2and ground. U1 is used as a differential amplifier, which converts thefloating TACH+/CAP− tachometer signal to a single-ended, groundreferenced tachometer signal without transients.

d. Pressure Sensor Mounting holes for the pressure sensor are provided,as well as a bypass capacitor and a pcb footprint for an optional rcfilter. The power, ground, and signal output lines for the pressuresensor are completely isolated from the rest of the PCM controllercircuit and layout.

Thus, provided in certain embodiments are animal containment systemblowers comprising two or more fans, a fan motor driving each fan, a fanspeed controller in connection with each fan motor, and one or more airpressure or airflow sensors in connection with the fan speed controller.In such embodiments, the controller sometimes increases or decreases thespeed of one or more fan motors and adjusts the air pressure to a setlevel and/or the airflow to a set level based upon one or more signalsfrom the one or more sensors corresponding to air pressure or airflow.The fans in the blower sometimes are oriented in series.

Provided also herein are methods for adjusting air pressure or airflowin an animal containment cage to a set level, which comprise sensing airpressure or airflow in the animal containment cage unit or an airconduit connected thereto, and increasing or decreasing the speed of oneor more fan motors in a blower assembly comprising two or more fans anda fan motor separately driving each fan until the air pressure orairflow reaches the set level. In certain embodiments, the two or morefans are in series.

Provided also is a controller that regulates airflow or air pressure inan animal containment system comprising a user interface and aprocessor, where the user interface comprises an air pressure and/orairflow setpoint input function; and the processor generates a fan speedsignal for one or more blowers based on the setpoint and an airflow orair pressure signal from one or more sensors in the animal containmentsystem. The controller sometimes is connected directly (e.g., by wire orcable) to the one or more blowers, and it sometimes is in wirelesscommunication with the one or more blowers. The controller sometimes isconnected directly (e.g., by wire or cable) to the one or more sensors,and it sometimes is in wireless communication with the one or moresensors.

Airflow

Ventilated cages flush contaminated air and heat that accumulates in thecage due to one or more contained animals. One approach is introducinglarge flow rates in hopes to keep the cage bedding dry and to evacuateammonia and other gases. Some approaches, however, allow for large areasof recirculation or bypass. The latter approaches can allow dirty air tore-circulate without exiting the cage for several minutes.

Cages provided herein allow for transverse cage airflow designed tominimize air recirculation and bypass, thereby providing efficient useof airflow for air exchange and temperature regulation. In someembodiments, provided is an animal containment cage comprising a coverand a base, where the cover comprises an air inlet and an air exit, abaffle between the air inlet and air exit that extends downwards intothe interior of the cage, and air flows downward from the inlet, throughthe cage interior and out the exhaust exit. In certain embodiments, airflows in a substantially U-shaped pattern, and sometimes the cagecomprises nesting material for an animal and air flows in proximity toor through the nesting material. The air inlet sometimes is atsubstantially one end of the cover and the air exhaust exit is atsubstantially the end of the cover. The air inlet sometimes comprises anair supply connector, and the air exhaust exit sometimes comprises anarray of apertures and/or one or more air exhaust connectors. The bafflesometimes extends from one wall of the cage to the opposite wall, andsometimes is one or more surfaces of a feeding tray. The baffle often isin effective sealing connection with two walls of a cage (e.g., afeeding trough resting on two cradles, one in each of two opposingsidewalls) to prevent or substantially reduce airflow around bafflesides and permit airflow under the baffle.

Airflow, differential pressure and air-exchange rates can be evaluatedin a variety of manners. Described hereafter is an example of a testprocedure that can be utilized to measure effectiveness of the cageairflow for various cage systems. An optical apparatus shown in FIG. 43Aand FIG. 43B is prepared and utilized to quantify the ability of a cageto clear saturated water droplets or fog. A flexible heater is placed ontop of the bedding material to simulate the heat load of one or morecaged animals, such as five (5) mice. With external airflow to thesystem turned off (e.g., airflow from a rack is turned off), saturatedfog is injected into the cage. A laser is positioned in a first beamlocation selected from one or more beam locations, as shown in FIG. 43A.The heater, laser, and photodetector then are turned on. Next the dataacquisition system records data when the airflow system is turned on(e.g., airflow from a rack to the cage is established). A computerconverts photodetector signal into a strip chart of laser power (e.g.,light intensity at the detector) versus time. When the initial amount offog is present the photodetector reads a low laser power or lightintensity due to the majority of the laser light being scattered away bythe fog. After the cage airflow begins and clears fog the photodetectorreads an increasingly higher laser power or light intensity due to thereduction in fog concentration. The rate at which the measured laserintensity increases is related to the cage airflow and air exchangeeffectiveness. Systems may provide an air exchange rate of about 60exchanges per hour, about 50 exchanges per hour, about 45 exchanges perhour, about 40 exchanges per hour, about 35 exchanges per hour, about 30exchanges per hour, about 25 exchanges per hour, about 20 exchanges perhour, about 15 exchanges per hour, about 10 exchanges per hour, or about5 exchanges per hour.

Temperature regulation efficiency in cages may be linked to airflowparameters. Temperature readings can be acquisitioned from one or morethermocouples placed in the upper half of the cage (e.g., FIG. 43B).Temperature readings can be simultaneously acquisitioned while airflowand air exchange rates are determined. The ability of the system toremove hot air is related to the amount and the effectiveness of thecage airflow. If the air re-circulates or bypasses certain parts of thecage, the system will experience a higher temperature.

The same procedure can be repeated at multiple points along the side ofthe cage. The time constants can be averaged to determine effectivenessof airflow, air exchange and temperature regulation. These measurementscan be acquisitioned for different types of cages to determine theproper airflow rate or select the best cage for a particularapplication.

Animal Containment Systems

A component described above can be combined with one or more othercomponents described herein and/or with one or more other componentsutilized in an animal containment facility. For example, an animalcontainment system sometimes comprises one or more of the following: oneor more cages (e.g., cage base member, cover member and insert member);one or more rack units each comprising one or more rack modules; one ormore airflow assemblies (e.g., an air supply blower and/or an airexhaust blower); and one or more detection, monitoring or sensingdevices. In some embodiments, air is provided to cages by a centralairflow system in an animal containment facility, and sometimes air isprovided by an airflow system described herein (e.g., an airflowassembly joined to the top of a rack).

FIG. 44 is an isometric view of a system assembly embodiment with threerack modules. A tram assembly (560) allows for a mobile rack system. Thebase member of the tram assembly (560) also restricts airflow of thebottom most module. Each module (564) stores multiple cage assemblies(561). Ventilation is provided by a supply blower (762), air isexhausted from cages via an exhaust blower (763), which can be coupledto an optional mixing box (740).

Processes for Constructing and Using Animal Containment Systems

Provided are processes for constructing animal containment systems andusing components described herein. In an embodiment, provided is aprocess for replacing a cage in an animal containment system, whichcomprises: (a) removing a used cage that contains an animal from ananimal containment system comprising one or more cages, (b) transferringthe animal to an unused cage, or placing an animal not formerly housedin the system in an unused cage, (c) placing the unused cage in thecontainment system, and (d) repeating steps (a) to (c) within a periodof time. In some embodiments, provided are processes for replacing acage in an animal containment system, which comprise: (a) removing acage that contains an animal from an animal containment systemcomprising one or more cages, (b) transferring the animal to asingle-use cage, or placing an animal not formerly housed in the systemin a single-use cage, (c) placing the single-use cage in the containmentsystem, and (d) repeating steps (a) to (c) within a period of time. Insome embodiments, the period of time is 180 days or less, 150 days orless, 120 days of less, 90 days or less, 60 days or less, 30 days orless, or 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14,13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, or 2 days or less, or 1 day. Steps(a) to (c) often are repeated by continuously replacing cages only withunused, single-use cages and without replacing used cages withsterilized and/or washed cages that were formerly used to contain ananimal. Each used, single-use cage often is disposed of without washingor sterilizing it or re-using it to contain an animal.

The cage sometimes comprises a cage base, a cover member and an optionalinsert member. Often, all components of a cage (e.g., cage base, covermember, food tray) are unused before they are contacted with an animal.An unused, single-use cage often is comprised of newly manufacturedcomponents, components not washed in an animal containment facility,components not sterilized in an animal containment facility, andcomponents that are not re-used. An unused, single-use cage typicallynever before contained an animal, and an animal generally never wasplaced into it. A used cage often is removed from a rack unit in thesystem, often a rack unit comprising modules described herein, and anunused, single-use cage often is placed in the same position in the rackunit from which the used cage was removed. In some embodiments, theanimal containment system comprises one or more rack units, one or morerack modules, one or more cage detection system members and/or one ormore airflow system members.

Certain embodiments include processes for replacing a cage in an animalcontainment system, which comprise: (a) removing a cage that contains ananimal from an animal containment system comprising one or more cages,(b) transferring the animal to an unused single-use cage, (c) placingthe single-use cage of step (b) in the containment system, and (d)repeating steps (a) to (c) within 30 days or less. In certainembodiments, steps (a) to (c) are repeated within 14 days or less; ananimal never is or was placed in the unused, single-use cage unit beforestep (b); steps (a) to (c) are repeated continuously until the death ofthe animal; steps (a) to (c) are repeated continuously; the cage removedin step (a) is a single-use cage; and the cage removed in step (a) isdisposed. In certain embodiments, the containment system is an animalhusbandry containment system. Sometimes the walls of the single-use cageare constructed from a polymer and are about 0.01 inches to about 0.08inches thick, or about 0.01 inches to about 0.05 inches thick, about0.02 inches to about 0.06 inches or about 0.02 inches to about 0.03inches thick.

Also provided is a process for assembling a detachable rack unit thatreceives animal containment cages, which comprises: connecting two ormore rack modules to form a rack unit, where the rack modules aredetachable. The rack modules sometimes are connected in a verticalorientation, sometimes connected in a horizontal orientation, andsometimes are connected vertically and horizontally. In someembodiments, the rack modules are connected without tools. One or morerack modules used to assemble a rack unit sometimes comprise a mountedstructure that comprises a slidable member that can be reversiblyassociated with a cage and immobilize the cage on the rack module,embodiments of which are described herein.

Provided also is a process for cleansing a rack unit assembled from rackunit modules from an animal containment system, which comprises:disconnecting rack unit modules, washing each rack unit module, andconnecting cleansed rack modules to assemble a cleansed rack unit. Oneor more cleansed rack modules sometimes are connected to one another andsometimes one or more cleansed rack modules are connected to unused rackmodules (e.g., newly manufactured rack modules or rack modules that hadnot previously stored cages). In certain embodiments one or more washedrack modules are connected. In some embodiments, a rack unit isdisconnected and connected for rack module cleansing on a periodicbasis, such as every 180 days or less, 150 days or less, 120 days ofless, 90 days or less, 60 days or less, or 30 days or less. Rack modulessometimes are disconnected and connected by hand without tools. Rackmodules are cleansed using appropriate washing equipment and sometimessterilizing equipment.

Provided also are process for assembling a modular rack unit forcontaining animal cages, which comprise: connecting two or more rackmodules by joining rack unit modules by a connector, where the rackmodules are detachable. In certain embodiments, the connector isconnected without a tool.

The entirety of each patent, patent application, publication anddocument referenced herein hereby is incorporated by reference. Citationof the above patents, patent applications, publications and documents isnot an admission that any of the foregoing is pertinent prior art, nordoes it constitute any admission as to the contents or date of thesepublications or documents.

Modifications may be made to the foregoing without departing from thebasic aspects of the invention. Although the invention has beendescribed in substantial detail with reference to one or more specificembodiments, those of ordinary skill in the art will recognize thatchanges may be made to the embodiments specifically disclosed in thisapplication, yet these modifications and improvements are within thescope and spirit of the invention.

The invention illustratively described herein suitably may be practicedin the absence of any element(s) not specifically disclosed herein.Thus, for example, in each instance herein any of the terms“comprising,” “consisting essentially of,” and “consisting of” may bereplaced with either of the other two terms. The terms and expressionswhich have been employed are used as terms of description and not oflimitation, and use of such terms and expressions do not exclude anyequivalents of the features shown and described or portions thereof, andvarious modifications are possible within the scope of the inventionclaimed. The term “a” or “an” can refer to one of or a plurality of theelements it modifies (e.g., “a cage” can mean one or more cages) unlessit is contextually clear either one of the elements or more than one ofthe elements is described. The term “about” as used herein refers to avalue sometimes within 10% of the underlying parameter (i.e., plus orminus 10%), a value sometimes within 5% of the underlying parameter(i.e., plus or minus 5%), a value sometimes within 2.5% of theunderlying parameter (i.e., plus or minus 2.5%), or a value sometimeswithin 1% of the underlying parameter (i.e., plus or minus 1%), andsometimes refers to the parameter with no variation. For example, aweight of “about 100 grams” can include weights between 90 grams and 110grams. Thus, it should be understood that although the present inventionhas been specifically disclosed by representative embodiments andoptional features, modification and variation of the concepts hereindisclosed may be resorted to by those skilled in the art, and suchmodifications and variations are considered within the scope of thisinvention.

Embodiments of the invention are set forth in the claims which follow.

1. A ventilated thin-walled rodent containment cage comprising a baseand a cover, wherein: the cover and base are constructed from a polymer;the base comprises a wall or walls and a bottom; the wall or walls ofthe base are 0.01 to 0.03 inches thick; the cage is free-standing; andthe cage is in effective connection with a blower, a vacuum, or a blowerand a vacuum.
 2. The rodent containment cage of claim 1, wherein thewall or walls and sidewalls of the base are substantially imperforate,and the cover comprises an air inlet aperture and an air exhaustaperture.
 3. The rodent containment cage of claim 2, wherein air entersthe cage through the air inlet aperture, flows under a baffle in thecage, and exits the cage through the air exhaust aperture, whereby theair flows in a substantially U-shaped flow pattern in the cage.
 4. Therodent containment cage of claim 3, wherein the baffle is one or moresurfaces of a food tray.
 5. The rodent containment cage of claim 1,which is in effective connection with a blower.
 6. The rodentcontainment cage of claim 1, which is in effective connection with avacuum.
 7. The rodent containment cage of claim 1, which is in effectiveconnection with a blower and a vacuum.
 8. The rodent containment cage ofclaim 1, which comprises a filter in effective connection with thecover.
 9. The rodent containment cage of claim 8, which comprises afilter shield, wherein: the filter shield is between the interior of thecage and the filter, and the filter shield comprises a surface withapertures that is offset from the filter and covers the filter.
 10. Therodent containment cage of claim 1, wherein the cage is free-standing ina rack.
 11. The rodent containment cage of claim 10, wherein the cage isone of a plurality of free-standing cages in a rack.
 12. The rodentcontainment cage of claim 1, wherein the polymer is polyethyleneteraphthalate.
 13. The rodent containment cage of claim 1, wherein thepolymer is polyvinyl chloride.
 14. The rodent containment cage of claim1, wherein the polymer is polyethylene.
 15. The rodent containment cageof claim 14, wherein the polymer is high-density polyethylene.
 16. Therodent containment cage of claim 1, wherein the polymer ispolyethylenefluoroethylene.
 17. The rodent containment cage of claim 1,wherein the polymer is polystyrene.
 18. The rodent containment cage ofclaim 17, wherein the polymer is high-density polystyrene.
 19. Therodent containment cage of claim 1, wherein the polymer is anacrylnitrile butadiene styrene copolymer.
 20. The rodent containmentcage of claim 1, wherein the polymer is polypropylene.
 21. The rodentcontainment cage of claim 1, wherein the cover and the wall or walls ofthe base are 0.01 to 0.02 inches thick.
 22. The rodent containment cageof claim 1, wherein the cover is 0.01 inches to 0.03 inches thick. 23.The rodent containment cage of claim 2, wherein the air inlet apertureand air exhaust aperture are located on the top of the cover.
 24. Therodent containment cage of claim 1, wherein the air flows through thecage at a rate of about 5 cage exchanges per hour to about 60 cageexchanges per hour.
 25. A ventilated thin-walled rodent containment cagecomprising a base and a cover, wherein: the cover and base areconstructed from a polymer; the base comprises a wall or walls and abottom; the wall or walls of the base are 0.01 to 0.03 inches thick; thecover comprises an air inlet aperture and an air exhaust aperture; thecage is free-standing; the wall or walls and sidewalls of the base aresubstantially imperforate; the air inlet aperture is in effectiveconnection with a blower, or the air exhaust aperture is in effectiveconnection with a vacuum, or the air inlet aperture is in effectiveconnection with a blower and the air exhaust aperture is in effectiveconnection with a vacuum; and air enters the cage through the air inletaperture, flows under a baffle in the cage, and exits the cage throughthe air exhaust aperture, whereby the air flows in a substantiallyU-shaped flow pattern in the cage.
 26. The rodent containment cage ofclaim 25, wherein the wall or walls and sidewalls of the base aresubstantially imperforate.
 27. The rodent containment cage of claim 26,wherein the air inlet aperture and the exhaust aperture are located onthe top surface of the cover.
 28. The rodent containment cage of claim25, wherein the baffle is one or more surfaces of a food tray.
 29. Therodent containment cage of claim 25, wherein the air inlet aperture isin effective connection with a blower.
 30. The rodent containment cageof claim 25, wherein the air exhaust aperture is in effective connectionwith a vacuum.
 31. The rodent containment cage of claim 25, wherein theair inlet aperture is in effective connection with a blower and the airexhaust aperture is in effective connection with a vacuum.
 32. Therodent containment cage of claim 25, which comprises a filter ineffective connection with the cover.
 33. The rodent containment cage ofclaim 32, which comprises a filter shield, wherein: the filter shield isbetween the interior of the cage and the filter, and the filter shieldcomprises a surface with apertures that is offset from the filter andcovers the filter.
 34. The rodent containment cage of claim 25, whereinthe cage is free-standing in a rack.
 35. The rodent containment cage ofclaim 34, wherein the cage is one of a plurality of free-standing cagesin a rack.
 36. The rodent containment cage of claim 25, wherein thepolymer is polyethylene teraphthalate.
 37. The rodent containment cageof claim 25, wherein the polymer is polyvinyl chloride.
 38. The rodentcontainment cage of claim 25, wherein the polymer is polyethylene. 39.The rodent containment cage of claim 38, wherein the polymer ishigh-density polyethylene.
 40. The rodent containment cage of claim 25,wherein the polymer is polyethylenefluoroethylene.
 41. The rodentcontainment cage of claim 25, wherein the polymer is polystyrene. 42.The rodent containment cage of claim 41, wherein the polymer ishigh-density polystyrene.
 43. The rodent containment cage of claim 25,wherein the polymer is an acrylnitrile butadiene styrene copolymer. 44.The rodent containment cage of claim 25, wherein the polymer ispolypropylene.
 45. The rodent containment cage of claim 25, wherein thecover and the wall or walls of the base are 0.01 to 0.02 inches thick.46. The rodent containment cage of claim 25, wherein the cover is 0.01inches to 0.03 inches thick.
 47. The rodent containment cage of claim25, wherein the air flows through the cage at a rate of about 5 cageexchanges per hour to about 60 cage exchanges per hour.